The answer is C: Parable.
This story of The Boy Who Cried Wolf, Wolf contains a message with a moral lesson in the line of "a liar is not believed even when he tells the truth". This is a parable, a figure of speech, which uses a short story that expresses an overall point, a moral or spiritual lesson. The word parable comes from the Greek, meaning "comparison." It is an easy way to explain complicate lessons.