#18 - Some potential anticancer drugs work by depriving

[Dave Killoran]

Complete Question Explanation

Must Be True. The correct answer choice is (C).

The stimulus is a Fact Set which discusses certain anticancer drugs, and explains that some work by stopping tumors from getting blood vessels. The creation of blood vessels is called angiogenesis (don't be distracted by this scientific term!), and these drugs stop that process. Interestingly, these same drugs seem to prevent obesity in rodents.

The stimulus is fairly short, and doesn't contain a huge amount of information, so if things seem to make sense, move quickly to the answer choices.


Answer choice (A): Just because certain anticancer drugs can act on different entities does not mean those entities are automatically similar, and certainly there is no basis to conclude that structurally tumor cells are more similar to fat cells than any other cells.

Answer choice (B): This is an outstanding trap answer! The test makers always examine whether you can read closely, and this answer provides a perfect example of that. The stimulus was clear in saying that these drugs "prevent obesity," but this answer references "to lose weight." Those two concepts are not identical, and thus this answer choice is incorrect.

Answer choice (C): This is the correct answer choice. The question stem is a Most Strongly Supported variant of Must Be True, and this answer makes sense based on the statements in the stimulus. The author established that tumors are stopped by cutting them off from new blood vessels, and it appears that fat cells may also need blood vessels since they are affected in a way that stops them from growing at least to some extent.

Answer choice (D): There is no information in the stimulus that supports this connection between cancer and a higher likelihood of obesity in rodents.

Answer choice (E): Note that "vital nutrients" did not appear anywhere in the stimulus, so making a connection here is tenuous at best. Students who chose this answer often felt it was based on common sense, but the standard for answers here is not common sense but rather the statements in the stimulus.

[lsatdreamecometrue]

Hi! I can understand why A, B, D, E can’t be inferred from the stimulus, but I don’t know how we can assume fat tissue “depends on” the angiogenesis. I thought “depend on” would mean a conditionality, and I agree there’s a correlation between the growing of fat tissue and blood vessels. Does C also contain a minor jump in the reasoning? And is it because C is the most provable one among all the five choices, so it is the correct answer? Thanks.

[KelseyWoods]

Hi lsatdreamcometrue!

Great job being tough on those answer choices and paying attention to the precise wording! You are correct that saying that fat tissue depends on angiogenesis to grow is a little stronger than we can definitively prove. But, as you observed, we're always looking for the answer choice that is the most provable out of the answer choices we have. And, as Dave mentioned above, this is really a Most Strongly Supported question, which is a variant of Must Be True (the question stem states: "The statements above, if true, lend the strongest support to which one of the following?"). Most Strongly Supported questions can be approached in basically the same way as Must Be True questions, but the answer choice usually ends up being slightly less provable than it might be in a Must Be True question, as we have with answer choice (C) for this question. So the threshold for provability is slightly less with a MSS question, even though in both MSS and MBT, you're always looking for the answer choice that is the most provable out of your five options.

Hope this helps!

Best,
Kelsey

[electiondistraction]

Hi,

Thanks for the explanations above. However, I'm still confused about the logical jump being made in C (I originally chose B). Just as we can't assume that losing weight == obesity, how can we make the connection between growing fat tissue and obesity? I flagged this question when I was going through as I was between B + C, but I ultimately went with B because I thought "probably" was a more supported statement than the much stronger "depends on" language used in C.

How can I go about this question differently to help me get the right answer?

[Adam Tyson]

The first thing to notice, electiondistraction, is the distinction that Dave pointed out in the main explanation in this thread. Answer B makes an unsupported leap from something preventing obesity to that same thing helping to lose weight. Maybe stopping angiogenesis will slow or stop the growth of fat tissue but do nothing to reduce it?

As for answer C, selecting this one requires knowing that obesity means having excessive body fat. It's not just being heavy, which might be caused by things other than fat tissue, but is about the fat. The authors of the test apparently determined that it is reasonable for someone taking the LSAT to know that, and that's why C is an acceptable answer here. If angiogenesis creates blood vessels, and if stopping that process can prevent obesity, it is a reasonable inference that fat tissue needs to be fed by blood vessels.

We don't have to like that answer, but we do have to recognize that it is better than any of the other choices, and that means carefully catching the trap laid for us in answer B. We do have information about a link between blood vessels and fat, but we have no information linking prevention of obesity to weight loss.

[electiondistraction]

Thanks, Adam!

[conorrjohnston]

Omg. This question was SO annoying to me. Literally none of the answers looked great to me, and I even tried to imagine what the LSAC was thinking when they authored it- which lead me to answer choice E.

I know, I know. Answer choice E sucks. I assumed that blood cells = vital nutrients which I shouldn't have, but I for the life of me did NOT see C even remotely being correct. In past questions, I've seen that an answer was wrong because it assumed from a unrepresentative sample information, which is exactly why I immediately ruled out C because I thought it was LSAC trying to trap me into making assumptions about the information presented. I thought that, okay great, rodents can have their obesity prevented with angiogenesis, but that doesn't inform about fat cells in general OR fat cells in humans! Just rodents! In fact, results in real life about lab rats are often NEVER translated conclusively and always taken with a grain of salt! Im so confused on how we got to answer choice c. EVEN SO, im so confused on how fat cells can DEPEND on angiogenesis. It both generalizes the results and makes it DEPENDENT. I thought this answer choice sucked! Please help!

[Luke Haqq]

Hi conorrjohnston!

Perhaps this answer choice didn't seem ideal because, as Dave and Kelsey underscore above, this is a Most Strongly Supported variant of Must Be True questions. Typically on Must Be True questions, the right answer choice necessarily follows from what is in the stimulus. In this Most Strongly Supported type of question, it's sufficient that one answer choice is better than the other four, even if it doesn't fully seem to follow.

Here, it might help to think of cause and effect going on in the stimulus, with the drug and its deprivation of blood vessels as the cause. One effect of this cause is that it helps stop tumors from growing. As it turns out, the drug also has another effect--preventing obesity. This strongly suggests that the same cause (depriving blood vessels) leads to this effect of preventing obesity, which is to suggest that fat tissue, like tumors, require blood vessels and angiogenesis to be able to grow.