In the passive voice sentence "A cheque was given to me by Rohan," the subject is the receiver of the action ("me"), the verb is "was given," and the doer of the action is "Rohan."
To transform it into the active voice, we need to make the doer of the action the subject and rephrase the sentence. So, "Rohan gave me a cheque" is the correct active voice transformation. In this sentence, "Rohan" is the subject, "gave" is the verb, and "me" is the receiver of the action.