Explanation :
The sum of kinetic energy and potential energy is called mechanical energy.
The kinetic energy is possessed by an object by virtue of its motion and the potential energy is due to height of the object under the action of gravity.
Mathematically,
\(KE=\dfrac{1}{2}mv^2\)
v is the velocity of the object
\(PE=mgh\)
h is the height from ground
We know that the potential energy at topmost point is maximum and it is least at ground.
So, from the given figure it is clear that the ball in box C has less potential energy than the ball in box B.
Hence, the correct option is (d) "The ball in box C has less potential energy than the ball in box B".
