An Observer Monkey That Is Not Afraid of Snakes Watches

An observer monkey that is not afraid of snakes watches another monkey that becomes very afraid when it sees a snake. The observer monkey may or may not become afraid of snakes, depending on

A) whether or not the other monkey screams and makes gestures.
B) whether or not it can see the snake as well as the other monkey.
C) whether it is older or younger than the frightened monkey.
D) whether or not it has ever been bitten by a snake itself.