There is no post about this question. Here's my breakdown. The question asks what the author indicates that all politicians agree about.
(B) Is unsupported and not in the text. The author does mention the use of military to quell civil disorder, but this is in the context of questioning the claims of at least some opponents. This means that this is not something that all can agree on. Even if you're tempted by this answer, remember the question is specifically asking about politicians - at this point in the text the author is speaking against "opponents" more generally.
(C) is contradicted by the text - Lines 24-25 note this is something that "might be objected" - means there is a disagreement.
(D) is not supported - there is a debate in the text over needs - there is not universal agreement that its scope should be expanded
(E) This is a major debate in the text - no agreement
(A) is the best answer - lines 40-44 directly support. Also keep in mind that this is part of the passage that is specific to all politicians. Politicians is the key word here and even if you were struggling with the content of the question, you should get this right from the limiting question.