LSAT Explanation PT 20, S1, Q19: No one in the French department

LSAT Question Stem

The pattern of reasoning displayed in the argument above is most closely paralleled by that in which one of the following arguments? 

Logical Reasoning Question Type

This is a Parallel question. 

Correct Answer

The correct answer to this question is D. 

LSAT Question Complete Explanation

This is a Parallel Reasoning question, which asks us to identify an answer choice that closely parallels the reasoning used in the given argument. The argument in the passage can be summarized as follows:

Premise 1: No one in the French department to which Professor Alban belongs is allowed to teach more than one introductory level class in any one term. (A -> /B)

Premise 2: The only language classes being taught next term are advanced ones. (C -> /B)

Conclusion: It is untrue that both of the French classes Professor Alban will be teaching next term will be introductory level classes.

In this case, both premises independently prove the conclusion. We need to find an answer choice that has two independent premises that both prove the conclusion.

a) This answer choice contains a conditional Repeat form, where the two premises work together. Since the structure of the answer is different from that of the stimulus, this answer choice is incorrect.

b) Only the first premise in this answer choice proves the conclusion; the second premise is irrelevant to the conclusion. Therefore, this answer is incorrect. Additionally, the conclusion in this answer choice is different from that in the stimulus.

c) This answer choice can be eliminated for two reasons: 1) The reasoning used is invalid, and 2) The two premises work together and are not independent as in the stimulus.

d) This is the correct answer. Each premise in this answer choice separately supports the conclusion, which closely parallels the reasoning used in the passage. Note that the negative term in the conclusion of the answer choice is not a factor that should be considered. For the purposes of matching the conclusion, "will be" and "will not be" are identical.

e) This answer choice is similar to answer choice (A) and contains a valid form of reasoning based on the Repeat form. However, the two premises work together, and neither proves the conclusion alone. Thus, this answer choice is incorrect.