The correct option is B genuine
The word 'phony' refers to someone not genuine or fraudulent.
Option A, ugly refers to being unpleasant and repulsive.
Option B, genuine refers to being real and authentic.
Option C, unreal refers to being imaginary or illusory.
Option D, beautiful refers to pleasing the sense or mind.
Thus, according to the meaning, the word 'genuine' is the opposite of the word 'phony'.