A man is running with a tennis ball in his hand. On his left is a bull's-eye target painted
on the ground. As the man passes the target, he tries to drop the ball on it. The ball
falls to the side of the target, missing the bulls-eye. The ball did not drop straight
down under the force of gravity because the man also acted on the ball with

O a horizontal force.
O a downward force.
O an upward force.
O a backward force.