Answer
Choice C.
Work Step by Step
The moral is not to ignore the vector nature of momentum and impulse.
Consider the ball’s momentum just when it arrives at home plate. Call the magnitude of the momentum p.
If the ball is stopped, its final momentum is zero and the change in momentum (impulse) has magnitude p.
If the ball is popped straight up at the same speed, its final momentum is straight upward with magnitude p, and the change in momentum (impulse) has magnitude $p \sqrt{2}$.
If the ball is hit backward at the same speed, its final momentum is backward with magnitude p, and the change in momentum (impulse) has magnitude 2p.