Answer:
The ball hitting the bat.
Explanation:
It is given that, a batter swings at a baseball. When the ball is being hitted by the bat, the action force acting on it is 5 N. Let R is the reaction force. It is equal to the action force but it acts in the opposite direction as per Newton's third law of motion.
The action and reaction forces acts on two different objects. Here, if the action force is " bat hitting the ball" then the reaction force will be "the ball hitting the bat" with a force of -5 N.
Hence, the correct option is (d) "the ball hitting the bat".
