Error spotting (voice: missing auxiliary in passive): Identify the erroneous part (A/B/C) — choose D if there is no error — 'The meeting adjourned abruptly / by the Chairman after / about three hours of deliberation. / No error.' Ensure correct passive construction for formal minutes.

Concept/Approach: Passive formation
When an external agent performs the action ('by the Chairman'), the verb must be in the passive: was/were + past participle. 'Adjourn' here is transitive.

Step-by-step correction
A: Insert auxiliary: 'The meeting was adjourned abruptly by the Chairman after about three hours of deliberation.'

Verification
Active alternative: 'The Chairman adjourned the meeting abruptly …'

Common pitfalls
Omitting the auxiliary in passive voice; confusing intransitive vs. transitive uses.

Final Answer
A — Use 'was adjourned' for the passive with expressed agent.