She is very keen . . . . . . . . going abroad, for higher studies.

A. at

B. on

C. for

D. over

Answer: Option B

Solution(By Examveda Team)

The phrase 'keen on' refers to a state of the human mind where you are very enthusiastic or excited about the event.
It refers to a state when a person looks forward to something with all of its energy.
Thus, we use the preposition 'on' with keen in the given sentence as the sentence talks of an event a person is looking forward to.