The correct answer is (C).
(C) Flaw
Step 1: Identify the Question Type
The question asks why the argument is flawed, making this a Flaw question.
Step 2: Untangle the Stimulus
The author concludes that Ishiko must be a good manager. The evidence is that Ishiko can defuse tension, and defusing tension (along with understanding people) is needed to be a good manager.
Step 3: Make a Prediction
This is a classic case of confusing necessity with sufficiency. Look at the stimulus in Formal Logic terms. According to the first sentence, if one is a good manager, then that person must understand people and be able to defuse tension:
If good manager _ understand people AND defuse tension
The next piece of logic says that anyone who can defuse tension must understand people. So, if one can defuse tension, then that person can also understand people:
If defuse tension _ understand people
It is given that Ishiko can defuse tension. By the second piece of evidence, she must also be able to understand people. She now meets the requirements for a good manager, as presented in the opening sentence. However, those skills are merely necessary. They do not guarantee (i.e., they are not sufficient to know) that she is a good manager. The author makes that mistake, treating the necessary skills as if they were a sufficient.
Step 4: Evaluate the Answer Choices
(C) accurately describes this commonly tested LSAT flaw.
(A) is a Distortion. By the second piece of logic, defusing tension is a quality that is sufficient to show an understanding of people. However, the author never treats defusing tension as necessary for understanding people. It's said to be necessary for being a good manager, but the author doesn't even get that right, treating it as sufficient.
(B) is a Distortion. Defusing tension is not a quality that correlates with being a good manager. It's a quality that is necessary (i.e., must be present) to be a good manager. And the author doesn't say it "results from" being a good manager. The author suggests it causes Ishiko to be a good manager, or at the very least is sufficient to indicate that she's a good manager.
(D) is irrelevant. How managers defuse tension has no bearing on the argument. The only issue is if they can or not.
(E) is a Distortion. The author does make an assumption about a quality (defusing tension) that all good managers have. However, the author is not assuming Ishiko must have that quality. That's already known. The assumption is that having that quality makes her a good manager.
