LSAT Explanation PT 19, S2, Q15: Because of the lucrative but illegal

LSAT Question Stem

Which one of the following is an assumption required by the argument? 

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

First, let's break down and analyze the argument in the passage. The argument's structure is as follows:

Premise: The lucrative but illegal trade in rhinoceros horns has led to a certain rhinoceros species being hunted nearly to extinction.

Conclusion: Periodically trimming off the horns of all rhinoceroses would be an effective way to ensure the survival of that species by eliminating the motivation for poaching.

To make this more understandable, let's use a simple analogy. Imagine a popular type of candy that is being stolen from stores frequently. The argument is saying that if we remove the candy's attractive packaging, people would no longer want to steal it, thus ensuring the candy's continued availability in stores.

Now, let's come up with an "Evaluate" question for this argument: "Would trimming the horns of rhinoceroses have any negative effects on their survival?"

The question type for this problem is Necessary Assumption, which means we need to find an assumption that the argument relies on in order to be valid.

Let's go through the answer choices:

a) Most poachers who are discouraged from hunting rhinoceroses are not likely to hunt other animals for their horns.

- This answer choice is not relevant to the argument, as it discusses other animals instead of the specific rhinoceros species in question.

b) At least some rhinoceroses whose horns are periodically trimmed off will be able to attract mates.

- This is the correct answer choice. It is necessary for the argument because if rhinoceroses cannot attract mates after having their horns trimmed, the species' survival would still be in jeopardy, negating the argument's conclusion.

c) Poachers hunt at least some immature rhinoceroses whose horns have not yet started to develop.

- This answer choice weakens the argument, as it implies that removing the horns might not be enough to deter poachers.

d) The demand for rhinoceros horns will remain constant even if the supply decreases after the periodic trimming-off of the rhinoceros horns has begun.

- This answer choice is not necessary for the argument, as it discusses the demand for horns rather than the survival of the rhinoceros species.

e) Rhinoceroses whose horns have been trimmed off are unable to defend themselves against predators.

- This answer choice also weakens the argument, as it suggests that trimming the horns could have negative consequences for the rhinoceroses' survival.

In summary, the correct answer choice is (b), as it addresses a necessary assumption for the argument to be valid: that rhinoceroses whose horns are trimmed can still attract mates and ensure the survival of their species.