Change the following from active to passive:
They had sent the invitations by courier.
Show answer & explanation
Correct answer: C
Explanation
Active sentence:
“They had sent the invitations by courier.”
Tense: Past Perfect (had + past participle)
Rule for Passive Voice in Past Perfect:
Object + had been + past participle + by + subject
Object = the invitations
Correct passive form:
The invitations had been sent by courier.
Other options either change tense or use incorrect structure.