Answer:
The antonyms you could use are Disappear or Vanish.
C would be my best guess but idk.
Option A: How well do elements of the text help the text achieve its goals?
The two last options are related with the interests of the reader and not only with the text. The option B, is not exactly about the text but more about the author. The option A really intends to assesses the text.
The answer is A. Conflict
