The correct option is D An order for a camera has been placed by me.
The correct answer is ‘An order for a camera has been placed by me.’ In the passive voice, the receiver of the action, ‘An order for a camera’ appears first in the sentence and as the receiver is singular, the singular form of the helping verb, ‘has’ is used. It is followed by the ‘be’ verb form ‘been’, the past participle of the main verb, ‘placed’, the preposition ‘by’ and the doer of the action ‘I’ which changes to the object pronoun ‘me’.