The deceiver's representing the self as good to an other whose frame of mind was less than discerning, artfully ________ virtue, was an important part of the movement of the evil gesture.

This sentence mentions two points that describe the course of actions of a person who is determined to harm others (deceiver) i.e. a mentally ill person. One is - they present themselves good to those who have less power to judge them (less than discerning) and other is they tactfully present goodness in a negative sense (artfully _____ virtue). Therefore, “extolling” (praising, lauding) in (3) and “burgeoning” (to grow or develop rapidly) are ruled out; being positive connotations. Neither can they “assuage” (to lessen, to calm) virtue nor can they “decresent” (decrease, lessen) virtue; hence options (1) and (5) are ruled out. But they can “burlesque” (to imitate derisively or comically; parody) virtue; which fits their course of action and therefore our prediction. Hence, (2) is the answer.