Three Idiots . . . . . really a watchable movie.

A. are

B. is

C. superb

D. do

Answer: Option B

Solution(By Examveda Team)

When you are speaking of or for yourself, use "am." When you are talking about a person or a thing (in the singular), use "is." When you are talking to a person, and when you are talking about other people or things (in the plural), use "are." Here, it is talking about a single thing. Hence, is will be used.