Change the following from active to passive:
The committee had been debating complex amendments when the bell rang.

Correct option is B

The correct active/passive voice of the given sentence is (b).
Explain the rules of conversion (Active → Passive) with structure:
Active voice (Past Perfect Continuous):
· Structure: Subject + had been + V1-ing + Object
· Sentence: The committee + had been debating + complex amendments…
Passive voice (Past Perfect Continuous):
· Structure: Object + had been being + V3 + by + Subject
· Sentence: Complex amendments + had been being debated + by the committee…
Why option (b) is correct: It uses the exact passive structure required for past perfect continuous: had been being + V3.
Example (same rule):
Active: The team had been preparing the report.
Passive: The report had been being prepared by the team.
Explain why other options are incorrect:
· (a) “had had been” is a wrong and double-auxiliary construction; grammatically invalid.
· (c) “had be being” is incorrect because after “had” we need past participle (been), not “be”.
· (d) “had debated” removes the continuous aspect and also misses required auxiliaries for passive voice.