An adverb is a word that describes a verb.
Example: The eagle flew swiftly to catch its prey. In this case, the word "swiftly" describes the verb "flew", making it the adverb.
Sentence A does not contain an adverb.
Sentence B does not contain an adverb.
Sentence C contains an adverb. The word "carefully" describes the verb "checked".
Sentence D contains an adverb. The word "deeply" describes the verb "worried".
Sentence E does not contain an adverb.