This question says to determine which of the answer choices would most weaken the author’s argument. We’ll particularly focus on looking for something that directly weakens the conclusion, but we should keep in mind that weakening premises can also be an answer choice.
In this argument, the author concludes that any social philosophy that promotes chaos is a bad one, primarily because an acceptable philosophy must promote peace and order.
However, this should give you pause _ particularly the author’s substitution of the word chaos for anarchy. Initially the author defined anarchy as "the absence of government." While we don’t want to be overly demanding about how authors use words, now eliding this definition to pure "chaos" seems somewhat disingenuous.
A second problem - even accepting the author’s contention about the promotion of law and order _ is that the author also seems to assume that short-term "chaos" cannot lead to long term peace and order, or that chaos is necessarily the opposite of peace.
With these initial thoughts in mind, let’s look to the answer choices.
(A) describes precisely our concern above about chaos v. an absence of government. Let’s keep this for now.
(B) states that the argument is unconvincing. While this might be what we are aiming to show with a weakening question, this premise doesn’t give any specific reason to show that the argument is weak. For this reason, we should still stick with (A) over (B) in choosing a final answer.
(C) may be true in the "real world," but it has nothing to do with this argument and is in particular irrelevant because strength of numbers is not the reasoning the author relies upon.
(D) is wrong. It has two words we’ve seen in the argument _ "peace" and "flourish" _ but those words were not connected by the author in the way this answer choice suggests.
(E) may also be true in the "real world" like (C), but like (C) it insinuates something that the author simply did not do in the argument.
Hence our answer is (A). While (B) might be something that goes against the conclusion, it is extremely broad and lacks bite. (B) is nearly the equivalent of saying "The author is wrong." When evaluated from a purely logical standpoint, such an assertion should not be convincing by itself. You must, instead, provide a specific reason to weaken the text, as (A) does.
Have you noticed any other questions that have a tricky wrong answer like (B)?