Answer:
A. noun
Step-by-step explanation:
A "noun" refers to a name of a person, place, thing, location, event, etc.
In the sentence above, the word "audience" stands as a noun. In a specific sense, it is a collective noun. It is used to identify a group of people or spectators. This means that the audience is spectating on the beautiful dance of Shelly.
Take note that a "verb" is an action word, an "adjective" is used to describe a noun or pronoun while an "adverb" is used to describe a verb, an adjective or another adverb.