Babui had written the letter.Choose the correct passive form -

A The letter was written by Babui

B The letter was being written by Babui

C The letter had been written by Babui

D The letter was wrote by Babui

Correct Answer: Option C

Past perfect tense এ থাকা active voice কে passive voice এ রুপান্তর করার নিয়ম -object কে subject+had been +v3+by+subject কে object .