LSAT Question Stem

The city official's argument depends on assuming which one of the following? 

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The city official's argument has the following structure:

Premise 1: Springfield city codes classify pigs as livestock.

Premise 2: Individuals may not keep livestock in Springfield.

Conclusion: Amy would not be allowed to keep the pot-bellied pig as a pet.

The question type for this problem is Necessary Assumption, which means we need to find the assumption that is required for the argument to hold true.

An "Evaluate" question for this argument could be: "Does Amy live in Springfield?" The answer to this question would determine whether the city official's argument is valid or not.

Now, let's discuss each answer choice:

a) Amy lives in Springfield.

This is the correct answer choice. If we negate this answer choice, we get "Amy does not live in Springfield." If this is true, the official's argument falls apart, because the city codes where Amy does live might allow keeping livestock.

b) Pigs are not classified as pets in Springfield.

This is not an assumption required by the argument. If we negate this answer choice, we get: "Pigs are classified as pets in Springfield." Even if this were the case, a general prohibition of livestock is broad enough to prohibit all livestock, including livestock animals that are considered pets.

c) Any animal not classified as livestock may be kept in Springfield.

This is not an assumption required by the argument. Even if this weren't the case, that would not be problematic to the official's argument. If we negate this answer choice, we get "not any non-livestock animal can be kept in Springfield," which has no effect on the argument that Amy can't keep her livestock as a pet in Springfield.

d) Dogs and cats are not classified as livestock in Springfield.

This is not an assumption required by the official's argument. If we apply the Assumption negation technique, we get the following: "Dogs and cats are classified as livestock in Springfield." This would broaden the ramifications of the general livestock prohibition, but it would have no effect on the argument that Amy cannot keep her pig as a pet.

e) It is legal for pet stores to sell pigs in Springfield.

This is not an assumption required by the argument. Negating this choice: "It is illegal for pet stores to sell pigs in Springfield." This would have no effect on the argument that Amy is prohibited from keeping her new pet.