I am worried . . . . . . . . the exam.

A. in

B. about

C. on

D. of

Answer: Option B

Solution(By Examveda Team)

In the above sentence, a preposition is missing. And without a preposition the sentence is incomplete.
A preposition is a word that shows the relationship between a noun or a pronoun and some other word or element in the rest of the sentence.
The most suitable prepositions for the given sentence can be for, about etc.