#21 - In several countries, to slow global warming, many

[Administrator]

Complete Question Explanation

Assumption. The correct answer choice is (D)

Your task in this Assumption question is to select the answer that contains information necessary for
the conclusion to be valid. Rephrased for clarity, the argument proceeds:

Premise: in several countries, many farmers are planting trees on their land because of
government incentives provided to slow global warming

Premise: these incentives arose from research indicating that vegetation absorbs carbon
dioxide that might otherwise trap heat in the atmosphere

Premise: however, a recent study indicates that trees absorb and store carbon less
effectively than native grasses

Conclusion: thus, these incentives are helping to hasten global warming

Because there is no “rogue” information in this stimulus, your prephrase begins by recognizing that
this is a Defender model assumption question. The correct answer will most likely raise an objection
to the conclusion for the purpose of dismissing it.

Here, a weakness in the argument is that the conclusion implies the farmers are removing native
grasses in order to plant trees on their land in accordance with the government incentive program.
However, the first sentence stated only that “farmers are planting trees on their land.” Without some
indication that the more effective natural grasses are being removed in favor of the trees, there is no
evidence to support the conclusion that planting the trees is helping to hasten global warming. The
correct answer will likely raise this objection for the purpose of dismissing it.

The incorrect answers will not provide information required for the conclusion to be valid. Instead,
those choices may support the conclusion, while not being required information, have no effect on
the conclusion, or could undermine the argument.

Answer choice (A): The argument did not address carbon dioxide emission, but absorption. Since the
argument had nothing to do with emissions, this information has no effect on the conclusion.

Answer choice (B): The conclusion in the stimulus did not pertain to why farmers plant trees, and
this information has no effect on the conclusion.

Answer choice (C): The argument talked only about the effects of planting trees, not of what would
occur when trees are removed. So, this information has no effect on the conclusion.

Answer choice (D): This is the correct answer choice. For the conclusion that there is a negative
effect on global warming resulting from the farmers planting trees, it must be the case that the
land used for planting trees would be more effective at absorbing carbon without the farmer’s
intervention. This choice provides that information. If this choice is negated, such that none of the
trees planted in response to the incentives were planted where native grasses would otherwise be
growing, the conclusion that planting the trees is hastening global warming would be invalid.

Answer choice (E): While it may be the case that the governments would do better by promoting the
growth of native grasses, this argument was constrained to the effect of the program promoting the
planting of trees. So, this information has no impact on the conclusion.

[15veries]

Is A wrong because it only talks about the negative aspect of tree and not of grass?
Maybe grass does that too and since from A we dont know which emits more, we cannot say using this to conlude what the author says in the stimulus?

I thought the correct answer is weak because it only says "some."
Even though some may be true, how much it can affect the overall?
The word always gives me caution...because some can only mean "one." The impact would be really small right?

[David Boyle]

Is A wrong because it only talks about the negative aspect of tree and not of grass?
Maybe grass does that too and since from A we dont know which emits more, we cannot say using this to conlude what the author says in the stimulus?

I thought the correct answer is weak because it only says "some."
Even though some may be true, how much it can affect the overall?
The word always gives me caution...because some can only mean "one." The impact would be really small right?

Hello 15veries,

Answer A is wrong because regardless of grass, any negative effect of trees might be greatly outweighed by their positive effect.
As for answer D, "some" is not a problem. Answer D means "at least one tree planted is planted where native grasses would otherwise grow", pretty much. Without that, how would there be any conflict between trees and grass?

Hope this helps,
David

[lsattaker202]

Hello there I got the correct answer choice in Review D. However, in Assumption questions with answer choices the negation technique is useful. I consistently, struggle using it when conditional phrasing is present. Answer choice B for example contains unless. Is this the correct negation? ' Even if there is not an incentive to do so most farmers would plant any trees on their land'. Would another way (mechanistic) be to diagram the statement as usual. Plant Trees --> Incentive and then just negate (the necessary term) Incentive? Plant trees --> ~Incentive. Thank you!

[nicholaspavic]

Hi 202,

This is a great question! And a tricky two-step process that you almost have down.

Let's take a look at the specific language so that others can follow allong. Answer Option (B) states:
"(B) most farmers do not plant any trees on their land unless there is an incentive to do so"

You have to convert that unless statement first to the conditional:

If most farmers plant any trees on their land, then there is an incentive to do so.

Then, you have to negate it for our Assupmption Negation technique. Well done by adding "even" to your phrasing! So let's keep it in there and negate it to:

Even if most farmers plant any trees on their land, then there is not incentive to do so.

Note that the conclusion in the stimulus did not pertain to why farmers plant trees, and therefore this negated information has no effect on the conclusion.

Thanks so much for the great question and I hope this helps!

[lsattaker202]

Hello thank you for the reply. I just want to double-check the order of the assumption negation technique and ordering of conditions. For example a separate answer choice states,

People who attempt to diagnose their medical conditions are likely to do themselves more harm than good unless they rely exclusively on scientifically valid information. One staff member negated this answer choice as the following:

Even if people don't rely exclusively on scientifically valid information, people who self diagnose are not likely to do themselves more harm than good.

But if one uses the method Nicholas posted it would be as follows,

People who attempt to diagnose their medical conditions are not likely to do themselves more harm than good even if they do not rely exclusively on scientifically valid information.

Basically reversing the order but it means the same thing?

[Adam Tyson]

Correct! Negation need not be a purely mechanical act (although it often can be, with just an insertion or deletion of the word "not" in the right place). Look for a way to make the statement false. If it is conditional, make the necessary condition unnecessary (that's where "even if not" comes in). You can paraphrase and change wording to make it make sense and be simpler, so long as you do not change the overall meaning of what you are saying. You can often attack negations by inserting the phrase "It is not true that..." at the beginning of the answer choice, but from there you might want to tweak it some to make it sound more normal and sensible to your ear.

Good job, keep up the good work lsattaker202!

[Oneshot06]

Hi, I was stuck between D and E and ultimately chose E because when I negated it to “many govts. have been interested in promoting the growth of native grasses” it seemed to go against the conclusion that govt. incentives to plant trees hasten global warming. Could you please help me understand how and why to eliminate E? Thx

[Adam Tyson]

Your negation is good, oneshot, but the effect of that negation is not what you think it is.

Right now, I drink a lot of beer and eat a lot of cheese. My diet is preventing weight loss.

I'm interested in losing weight.

Does my interest in losing weight mean my diet is NOT preventing weight loss? Does my interest mean I am doing anything about it? Sadly, no - my butt is in a chair answering questions instead of out hiking, and I have cheese and beer nearby.

Like my problem, the governments in answer E have an interest, but that doesn't mean their incentives are not hastening global warming. They want to do the right thing, but they are not actually doing it. Their interest doesn't harm the argument, but is essentially irrelevant to it, just as my interest in weight loss is irrelevant to the harm I am doing as I drink this beer and eat this cheese.

Hope that helps. Bottoms up and bon appetit!

[Oneshot06]

Thanks Adam! So the word “interest” was the determining factor in why this answer choice was wrong. Just because the govts . have an interest doesn't mean they’ll actually follow through...I’m sure YOU can hike and type answers at the same time though!