Question

Identify the correct version of the sentence:
"Hardly had he entered the room when he was hearing the explosion."

• A. Hardly had he entered the room when he heard the explosion.
• B. Hardly he had entered the room when he heard the explosion.
• C. He hardly entered the room when he was hearing the explosion.
• D. No correction needed.

Hint:

\textbf{Tip:} In correlative structures like "Hardly...when", use past perfect for the first part and simple past for the second.