DIRECTIONS: in the following question, a part of sentence is bold. Below are given alternatives to the bold part which may improve the sentence. Choose the correct alternative. In case no improvement is required, choose “No Improvement” option.
Two of the biggest corporate firms in the world are Apple and IBM which both are in the computer business.

Options

A. a) which are both
B. b) both of which are
C. c) which are
D. d) No Improvement

Answer

B

Explanation

Here, both of which are is the right usage.