Why would an author use dramatic irony in a play?

A. to reveal the main character's inner thoughts to the audience but not to the other characters.
B. to increase the suspense or humor by having the audience know more than the characters.
C. to create humor for the audience by having a character say something but mean the opposite.
D. to have a character deliver an important speech to the audience or another character.

B. to increase the suspense or humor by having the audience know more than the characters.