Rewrite the sentence in the passive voice.
Sumanth was reading a book.

Correct option is A

The correct option is (a) A book was being read by Sumanth.
Definition of Active Voice: In active voice, the subject of the sentence performs the action.
Definition of Passive Voice: In passive voice, the subject of the sentence receives the action.
Tense identification: The sentence is in Past Continuous Tense.
Rule: In Past Continuous Tense, the structure for changing active to passive is:
Active voice: Subject + was/were + V1 + ing + Object.
Passive voice: Object + was/were + being + V3 + by + Subject.
Corrected sentence: A book was being read by Sumanth.