The culprits … when we entered the courtroom.

Analyze the question The sentence is: "The culprits ___ when we entered the courtroom." We need the verb form that fits the tense and meaning.

Explain the concept The clause "when we entered" is in the simple past tense. It marks a past point in time. The action in the blank was already in progress at that moment, so it needs a past continuous (progressive) passive form: was/were being + past participle.

The culprits don't interrogate themselves. They are the ones being questioned, so the verb must be passive.

Step-by-step solution

1. Time reference: "entered" is past tense, so the blank must be a past form.
2. Voice: "The culprits" receive the action, so we need the passive.
3. Subject: "culprits" is plural, so we use were.
4. Check the options: • A. were being interrogated: past continuous passive, plural. It fits. • B. are being interrogated: present continuous. It clashes with "entered". • C. will be interrogated: future. It does not fit a past event. • D. would be interrogated: future-in-the-past, which suggests something planned for later, not something already happening when we entered.

Answer: A. were being interrogated

The meaning is: while we walked into the courtroom, the culprits were already in the middle of being questioned.

Exam tip When a sentence has "when + simple past" (e.g., when we entered), look for an ongoing past action with was/were + -ing. Always check the tense of the time clause first, then match the subject (singular or plural) and the voice (active or passive).