Final answer:
The chorus is a person or group of people who act as the narrator in a story or play, providing commentary and background information, and is distinct from the protagonist, antagonist, and other characters.
Step-by-step explanation:
The chorus in the context of a story or play is Option 3: A person or group of people who act as the narrator. Historically, particularly in ancient Greek theatre, the chorus was composed of a group of characters who commented on the dramatic action and participated in it with a collective voice. They sometimes provided background and summary information to help the audience follow the story and occasionally interacted with the main characters, but they were separate from the protagonist and the antagonist. The chorus’s role can vary widely, from acting almost as another character in the play to just providing interludes and reflections on the play’s events.
While a chorus can sometimes be thought of as a secondary character, they are distinct from the main narrator, who tells the story, or the protagonist, who is the main character in the narrative. Similarly, the chorus is not the same as the antagonist, who is defined as a character or force that opposes the protagonist. Therefore, the most accurate definition of a chorus within the context of storytelling—particularly in drama—is a narrating group distinct from individual main and secondary characters.