LSAT Explanation PT 42, S2, Q25: A study of 86 patients, all

LSAT Question Stem

Which one of the following statements, if true, most seriously weakens the argument? 

Logical Reasoning Question Type

This is a Weaken question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

The question type for this problem is Weaken, which means we are looking for an answer choice that undermines the conclusion or the relationship between the premises and the conclusion.

First, let's analyze the argument in the passage. The argument is structured as follows:

Premise 1: 86 patients with disease T were divided into two equal groups; one group attended weekly support group meetings, and the other group did not.

Premise 2: After 10 years, 41 patients from each group had died.

Conclusion: Support group meetings do not help patients with disease T live longer.

An "Evaluate" question for this argument could be: "Did the patients who attended support group meetings live longer on average than those who did not?"

Now let's discuss the answer choices:

a) Of the 4 patients who survived more than 10 years, the 2 who had attended weekly support group meetings lived longer than the 2 who had not.

- This answer choice weakens the argument slightly, as it suggests that attending support group meetings may have helped the patients live longer. However, it only focuses on the 4 survivors, while the argument is based on the 41 patients who died in each group. Therefore, this answer choice is not as strong as another option.

b) For many diseases, attending weekly support group meetings is part of the standard medical treatment.

- This answer choice is irrelevant to the argument, as it discusses other diseases and not disease T specifically.

c) The members of the group that attended weekly support group meetings lived 2 years longer, on average, than the members of the other group.

- This is the correct answer choice. It directly weakens the argument by stating that the support group members lived longer on average than those who did not attend support groups, contradicting the conclusion in the passage.

d) Some physicians have argued that attending weekly support group meetings gives patients less faith in the standard treatment for disease T.

- This answer choice is irrelevant to the argument, as it discusses the faith of support group members, which is not related to the conclusion that support group meetings do not help patients with disease T live longer.

e) Everyone in the group whose members attended weekly support group meetings reported after 1 year that those meetings had helped them to cope with the disease.

- This answer choice is also irrelevant to the argument, as it discusses how well the two groups coped with the disease, not whether support group meetings help patients with disease T live longer.

In conclusion, the correct answer choice is (c), as it directly weakens the argument by stating that the support group members lived longer on average than those who did not attend support groups.