The correct answer is D. dissent.
To conform is to act in accordance with the standards or customs of a particular group or society. To dissent is to express disagreement or disapproval.
A. disappoint: to fail to meet the expectations of someone.
B. reform: to make changes to something in order to improve it.
C. deform: to change the shape or form of something in a way that is not normal or desirable.
Dissent is the most opposite of conform because it is the act of disagreeing with or opposing something. The other options are all actions that can be taken to change something, but they do not necessarily involve disagreement or opposition.