Choose the accurate direct speech version of the following sentence.
The detective inquired when I had departed from the office that afternoon.

Correct option is B

The correct direct speech is (b) The detective said, "When did you depart from the office that afternoon?"
Explain the rules of conversion in detail.
• Reporting verb + wh-clause: Indirect inquired when → Direct “When …?” (question form with a question mark).
• Back-shift of tense reversal: Indirect had departed (past perfect) typically back-shifts what was originally simple past in direct. Thus, Direct: did … depart.
• Pronoun change: I (speaker/reportee) → you in the detective’s direct question to the listener.
• Time expression: “that afternoon” can be retained in the quoted question when the narrative maintains the same temporal framing as the report (exam style often keeps it; alternatively some contexts may use “this afternoon,” but that changes deictic perspective).
Structure:
Direct Question: “When + did + subject + base verb + … ?”
Indirect Question: asked/inquired + when + subject + past perfect (for back-shifted past)
Example:
Direct: She asked, “When did you arrive?” → Indirect: She asked when I had arrived.
Information booster: In yes/no questions, indirect uses if/whether; in wh-questions, the wh-word replaces that/if. Also, question order (aux + subject inversion) appears only in direct speech; indirect speech uses statement order.