LSAT 35 - Section 1 - Question 19

Which one of the following is most strongly supported by the information above?

This is a Most Strongly Supported question.

Lathyrism, a debilitating neurological disorder caused by the consumption of the legume lathyrus sativus, is widespread among the domestic animals of some countries.

We’re told two facts about lathyrism in this sentence: (1) it’s widespread among the domestic animals of some countries, and (2) it’s a debilitating neurological disorder caused by eating a certain kind of plant.

Attempts to use rats to study lathyrism have generally failed.

We’ve tried to study this disorder in rats – but these attempts have mostly failed. Interesting – why have they failed? Are we going to start using some other animal in our studies? And can that animal be my neighbor’s Pomeranian?

Rats that ingested Lathyrus sativus did not produce the symptoms associated with the disorder.

This does provide an explanation of why using rats to study lathyrism hasn’t been useful – the rats that ate the plant that causes lathyrism don’t have the symptoms of lathyrism. Since we don’t see the symptoms in these rats, it’s tough to learn anything about lathyrism from them. For the sake of science, we need our test subjects to suffer the debilitating effects of this neurological disorder!

The stimulus doesn’t seem structured to lead to a particular conclusion. Let’s go to the answers and look for something that’s most strongly supported.

Answer Choice (A) The physiology of rats is radically different from that of domestic animals.

This may be a tempting answer, since it is a potential explanation for why rats don’t seem to experience the symptoms of lathyrism. But the problem is it’s far too speculative. We have no reason to think that this explanation is more likely than any other potential explanation.

Another issue is that even if we could say that some physiological difference in rats is why they don’t experience symptoms of lathyrism, that does not support the claim that rat physiology is radically different from domestic animals. “Radically different” means extremely different. But maybe there’s only a small difference that accounts for the rat’s resistance to the symptoms; we have no reason to think that there must be some extreme difference in physiology. Even a small difference in one’s bodily functions might lead to widely varying resistance to diseases.

Answer Choice (B) The rats did not consume as much Lathyrus sativus as did the domestic animals that contracted lathyrism.

This is similar to (A) in that it’s also offering a potential explanation of why rats did not exhibit symptoms. But we just don’t know how much the rats ate. It’s possible that they ate less than the domestic animals, and that this is why the rats didn’t experience the symptoms. But we don’t know – nothing in the stimulus speaks to the amount of the plants the rats ate.

Correct Answer Choice (C) Not all animal species are equally susceptible to lathyrism.

This is supported, because we know that rats don’t produce the symptoms of lathyrism, whereas at least some other animals do. The stimulus doesn’t explicitly say that other animals experience the symptoms, but the first sentence states that lathyrism is a “debilitating neurological disorder,” which means that it must have some effect on at least some animal in the world. If it didn’t, then it wouldn’t make sense to call the disorder debilitating. Since rats are affected differently from lathyrism compared to at least some other animals, that means lathyrism has varying effects on at least some animals in the world.

Sometimes people have a problem with the word “susceptible” in this answer. But susceptible means “liable to be influenced or harmed by a particular thing.” If rats don’t produce symptoms of lathyrism, but some other animal does, it’s fair to say that rats are less susceptible to lathyrism than the other animal. Rats are not as liable to be influenced or harmed by lathyrism.

Answer Choice (D) Most of the animals that can contract lathyrism are domestic.

“Most” means over half. The stimulus doesn’t support the claim that over half of animals that can get lathyrism are domestic. Although we know that lathyrism is “widespread among the domestic animals of some countries,” that doesn’t speak to what proportion of animals that can get lathyrism are domestic. For example, maybe lathyrism affects many cows, pigs, chickens, and hopefully, my neighbor’s Pomeranian. But it could be that lathyrism also affects lions, tigers, deer, wolves, monkeys, and every single wild animal in the world. The number of wild animals affected could be a lot greater than the number of domestic animals affected.

Answer Choice (E) Laboratory conditions are not conducive to the development of lathyrism.

Like (A) and (B), (E) is also an attempt to explain why the rats were asymptomatic. But we don’t know whether lab conditions are the reason that the rats mentioned in the stimulus didn’t produce symptoms of lathyrism. This explanation is possible but far too speculative since the stimulus doesn’t say anything that makes this explanation for the rats’ resistance to lathyrism any more likely than some other explanation (such as rats having some genetic resistance or other natural defense against lathyrism).