Which is an example of irony?
A. A firefighter rushes into a blazing house to rescue a cat and barely survives the ordeal.
B. A woman predicts that the baby she's carrying will be a boy, but the baby turns out to be a girl.
C. A boy who is angry at his parent, slips into an alley to avoid his mother and runs right into his father.
D. A man challenges another man to a duel, but only one of the men shows up to the duel.