6872. It took him a long time to come round after the operation.

✅ The correct answer is option A.
recover : return to a normal state of health, mind, or strength.

walk : move at a regular pace by lifting and setting down each foot in turn, never having both feet off the ground at once.

move : go in a specified direction or manner; change position.

eat : put (food) into the mouth and chew and swallow it.

come round: recover consciousness.

Synonym of come round is recover