Select the correct passive form of the given sentence.
We have looked at the plan carefully

Options

A. The plan is being looked at carefully
B. The plan has been looked at carefully
C. The plan have been looked at carefully
D. The plan was looked at carefully

Explanation

(b) The plan has been looked at carefully. (Correct) (a)The plan is being looked at carefully. (Tense has changed) (c)The plan have been looked at carefully. (Have is incorrect as plan is singular and have is plural.) (d)The plan was looked at carefully. (Tense has changed)