Rewrite the sentence in the active voice.
He was taken to the hospital by his friends.

Correct option is D

The correct option is (d) His friends took him to the hospital.
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 Simple Past Tense.
Rule: In Simple Past Tense, the structure for changing passive to active is:
Passive voice: Object + was/were + V3 + by + Subject.
Active voice: Subject + V2 + Object.
Corrected sentence: His friends took him to the hospital.