Choose the sentence with the adverb of manner out of the given options:

He left his family stealthily.

The correct answer is Option (3) - He left his family stealthily.

An adverb of manner describes how an action is performed.

• "stealthily" (quietly and secretly) describes how he left his family.

OTHER OPTIONS

• "He often makes mistakes."  (Often is an adverb of frequency, not manner.)
• "She is very intelligent."  (Very is an adverb of degree, not manner.)
• "She therefore decided to be a rich woman."  (Therefore is an adverb of reason, not manner.)