You Are Practicing Throwing Baseballs Long Distances with the Members

Multiple Choice

You are practicing throwing baseballs long distances with the members of your baseball team. At the same time that your partner throws the ball to you, another player across from you throws his baseball off-target, and it heads straight toward you. You hold your baseball glove up to catch your partner's ball, and you instinctively throw up your other arm to protect your face from the other incoming ball. The protective action of throwing up your arm is an example of a(n)

A) nerve net.
B) reflex.
C) effector cell.
D) blood-brain barrier.