What part of speech is the word in italics?

shelly's beautiful dance #thoroughly# captivated the audience.

noun

verb

adverb

adjective

The word in italics "thoroughly" is an adverb. (Option 3).

There are two things that help you identify the word as an adverb. First of all, the word ends in "-ly". This suffix is usually used to create adverbs. However, there are some adjectives that also end in "-ly". So, if you pay attention to what the word "thoroughly" modifies, you should be able to distinguish that it modifies the verb "captivated" and not the noun "dance". If a modifier explains or characterizes the action (the verb), it is an adverb.

i think the answer is c

you need need more details so we can understand what your asking us.