It presents the main idea of the entire composition
Compromising your viewpoints and behavior is bad generally: it will in the end only lead to frustration and will be a hindrance in achieving one's goals.
There are many situations in which compromising the viewpoint is bad, and one of the is an interpersonal conflict: it might solve the problem in a short-term, but not in a long term.
The answer is A. questions usually start with a helping verb or adverb.