Choose the right passive voice of - 'The Headmaster was addressing the teachers':

♦ Voice এর ক্ষেত্রে,

• Active voice কে Passive voice এ রূপান্তরের নিয়ম:
- Active Voice এর object‌ টি Passive voice এর subject হয়
- Tense অনুযায়ী Auxiliary verb
- মূল verb এর past participle
- Active voice এর subject টি Passive voice এর object হয়
- তার পূর্বে Preposition (By, with, at, to, in) বসে।

Active Voice: The headmaster was addressing the teachers.
Passive Voice: The teachers were being addressed by the headmaster.

Source: Advanced Learners Communicative English Grammar and Composition With Solution (For Class 9-10).