According to Aristotle, What Made Oedipus Rex and Medea Great

According to Aristotle, what made Oedipus Rex and Medea great works of art was that

A) they were outstanding examples of the Dionysian type of art.
B) they made us aware of the gap between the transcendent reality of the forms of beauty and goodness and the real world.
C) their characters and plots effectively evoked and cleansed their audiences of basic emotions such as fear and pity.
D) they taught people that the material world was passing away and so was of little value.