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 Administrator
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#31753
Please post below with any questions!
 Kdup
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#41949
Hi Powerscore,

I don't really understand why answer choice C is incorrect. I selected answer choice C because no where in the stimulus does it talk about other fields besides botany. Even if it were true, wouldn't it also be irrelevant to the argument. I eliminated D on the basis that the stimulus didn't give no reason to infer that the botanist had no techniques. I just thought that they didn't have the proper technique or one that was efficient.
 Luke Haqq
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#42021
Hi Kdup,

To begin, we should categorize this question as a Cannot Be True question (Of the following claims, which one can most justifiably be rejected on the basis of the statements above?). On a Cannot Be True question, of the 5 possible answer choices, 4 of them could possibly be true. The correct answer choice is the only one that can't be true based on the information given.

You're right that (C) is bringing in information that is not talked about in the stimulus. However, that just means we don't know whether or not answer (C) is true. In other words, that means, based on the information given (C) could be true. That's why (C) can't be the correct answer--the correct answer cannot possibly be true based on the stimulus. (C) could possibly be true.

By contrast, answer (D) states, "Botanists have no techniques for determining whether distinct plant species have been given distinct names." We know this is false because the stimulus states that "by using DNA analysis, botanists have shown that varieties of plants long thought to belong to the same species actually belong to different species." DNA analysis is thus a technique "for determining whether distinct plant species have been given distinct names," which is why (D) cannot be true and is thus the correct answer.
 kennypark17
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#50445
I thought D) was more along the lines of that there was no standardized naming technique of naming plants. The DNA analysis doesn't really say anything about the naming system of those plants.
 Sky Brooks
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#56789
Hi Kennypark17,

Answer choice D states, "Botanists have no techniques for determining whether distinct plant species have been given distinct names."
This statement is not about the technique of naming the plants, but rather about whether botanists have a technique for making sure that all different species of plants have actually been given different, distinct names. It is the having, or the not having, of the technique that matters.

The passage states, "And by using DNA analysis, botanists have shown that varieties of plants long thought to belong to the same species actually belong to different species." -- In other words, botanists can use DNA analysis to determine the actual species of a plant, despite what the name is. So they have the technique, it's DNA analysis.

Because this is a MUST BE FALSE question, D is the correct answer. The passage above directly refutes statement D, making it the correct choice.

Hope this helps!

-Sky Brooks
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 LawSchoolDream
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#104991
I intuitively got this question correct but was stuck with C as well. Can you please share why not c?

And also can you please share what indicators in stimulus and correct answer choice reveal cause and effect? I didn't quietcatch that.
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 Jeff Wren
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#105057
Hi LawSchoolDream,

Luke's post above explains why Answer C is incorrect.

Just to expand on his explanation, this is a Cannot Be True question, which is a fairly rare question type in logical reasoning. For these questions, you are looking for the answer that directly contradicts the information in the stimulus.

If an answer choice contains information outside of the scope of the information in the stimulus, then it doesn't directly contradict the information of the stimulus and is incorrect. In other words, that answer "could be true" based on the information in the stimulus. Answer C discusses fields other than botany. Since we know nothing about fields other than botany based on the information in the stimulus, this answer does not directly contradict the stimulus and is therefore wrong.

This question doesn't really involve causal reasoning.
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 LawSchoolDream
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#105110
Jeff Wren wrote: Thu Jan 25, 2024 10:11 pm Hi LawSchoolDream,

Luke's post above explains why Answer C is incorrect.

Just to expand on his explanation, this is a Cannot Be True question, which is a fairly rare question type in logical reasoning. For these questions, you are looking for the answer that directly contradicts the information in the stimulus.

If an answer choice contains information outside of the scope of the information in the stimulus, then it doesn't directly contradict the information of the stimulus and is incorrect. In other words, that answer "could be true" based on the information in the stimulus. Answer C discusses fields other than botany. Since we know nothing about fields other than botany based on the information in the stimulus, this answer does not directly contradict the stimulus and is therefore wrong.

This question doesn't really involve causal reasoning.

Thanks for expanding this further, its helpful!
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 Tyler1237
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#113774
Hello,

I got this question correct but I wanted to see if there was a better way for me to prephrase / attack the answer choices. For this question, I couldn’t come up with a prephrase and just picked off the obvious wrong answer choices. Is there a better way to do this, or to prephrase the correct answer choice?

I find myself just going to the answer choices without prephrasing in most cannot be true / must be true question types, then picking off the wrong ones instead of looking for the right one first. I feel like thinking of all the possibilities of what must or cannot be confirmed sometimes just takes too much time. The exception is those stimuli where it’s the set of conditional reasoning and formal logic statements. In those cases building a mental diagram is my prephrase.
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 Dana D
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#113799
Hey Tyler,

I think for MBT / cannot be true questions like this where you are given a set of facts rather than conditional logic your approach is spot on. The biggest thing is reminding yourself that the correct answer is going to either be directly supported by the stimulus (if a MBT) or directly contradict something in the stimulus (in a cannot BT).

If you're still trying to speed things up, when reading through answer choices to determine contenders vs. clear losers, I would try asking whether the answer choice is a "maybe true." For MBT or cannot be true questions, you're looking for a very definitive answer choice - there is either absolutely no way the answer can be true, or no way it can be false. If you read through the answer choice and think "I dunno - could be true, but might be false" that's an indicator that it doesn't fit the criteria. If you can't immediately identify it as a "maybe", then it should be a contender for the right answer. That should help you either identify the correct answer outright or at least narrow down the answers to two possibilities. Then you can test whether they are really "maybes" or if they actually must be true/cannot be true.

Hope that helps!

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