Transform it into passive voice:
They are watching a movie.

• Correct Answer: ঘ) A movie is being watched by them.

• Active Voice: They are watching a movie.
- They are watching - এটি Present Continuous Tense.
- Passive form হয়: am/is/are + being + verb এর 3rd form (past participle).

• Passive: A movie is being watched by them.

• Other options:
ক) A movie watched by them. - কোনো auxiliary verb (is/being) নেই। ভুল।

খ) A movie is watched by them. - এটি Simple Present tense-এ হয়েছে।

গ) A movie was being watched by them. - এটি Past Continuous tense.

Source: A Passage to the English Language, S.M. Zakir Hussain.