Select the option that expresses the given sentence in passive voice.
They were watching a movie on TV when their friends came.

Correct option is B

Active Voice: The subject performs the action expressed by the verb.
Passive Voice: The subject receives the action expressed by the verb.
The correct passive voice of the given sentence is (b) A movie on TV was being watched by them when their friends came.
Explanation:
This is past continuous tense, so passive structure is:
Structure:
· Active: was/were + V1-ing
· Passive: was/were being + V3
· Example:
· Active: She was writing a letter.
· Passive: A letter was being written by her.
· Other options:
· · (a) Incorrect form “was watching”.
· · (c) Changes meaning and tense.
· · (d) Tense mismatch: “is being watched” with “when their friend came”.