'I had written the letter.' বাক্যটির Passive form হবে-

A The letter was written by me.

B The letter had been written by me.

C The letter was being written by me.

D The letter was wrote by me.

Correct Answer: Option B

Past perfect tense যুক্ত active voice কে passive voice এ রুপান্তর করার নিয়ম-

Structure:
Object এর subject + had been + verb এর past participle form + by + subject এর object.
The letter had been written by me.