Yes, you're on the right track. The passage introduces the theory of philosophical anarchism, proceeds to describe a few criticisms of the theory, and then refutes these criticisms. Therefore, we know that the author accepts at least the few positions of the theory that it defended against criticism, and (B) is consistent with such a stance. (A) is incorrect because it is too strong to say that the author's defense of a few criticisms of certain elements of the theory translates to "ardent approval of most aspects of the theory." The words "ardent" and "most" constitute an overstatement that make (B) a better choice.
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