Correct option is D
Explanation:
The phrase “too strong to walk” is illogical — if someone is “too strong,” walking should not be a problem.
The correct phrase is “strong enough to walk.”
Correct Sentence:
He has recovered now and is feeling
strong enough to walk.
Grammar Rule:
· Use
“enough + to + base verb” to indicate sufficient ability
· e.g., He is tall enough to reach the shelf.