The is a small or large group of people that have gathered together to listen to a speaker.
a. source
b. receiver
c. audience
d. presenter

The answer is letter c. audience.  They can be fans who would listen to their favorite musician or what their favorite actor perform.  Or it could a group of people who are drawn together to an event out of curiosity.

there are no options provided but you can choose among the following gender-neutral pronouns: zir, hir, eir, vis, tem, eir.

in the normal course of maintaining a pronoun-antecedent agreement, we could have used the words his or her but since we are also required to use gender-neutral language, we need to replace it with its equivalent gender-neutral pronoun.