Answer: C - preclude : facilitate :: capitulate : withstand
In the first half of the analogy, preclude and facilitate are antonyms. To preclude means to prevent or prohibit, and to facilitate means to ease or assist. Therefore, look for the answer pair that contains antonyms. In choice (A), to affront means to insult or disrespect, so eliminate that choice. In choice (B), the words are synonyms; to besmirch means to defile or to make dirty. In choice (D), to ameliorate means to improve or upgrade, so eliminate that choice. The only answer choice that contains antonyms is choice (C). To capitulate means to surrender, resist, or withstand. Therefore, choice (C) is correct.