The correct sentence that displays proper subject-verb agreement is:
The people in the audience stand as the show ends.
The other sentences contain errors in subject-verb agreement:
- "The dialogue spoken by the actors make the crowd roar with laughter." (should be "makes")
- "The helpers working behind the stage comes out, too!" (should be "come")
- "The actors in the play returns to take another bow." (should be "return")