Work Energy Power

The answer is B. The two balls fell with the same acceleration so they reached the ground at the same time. The two ball are of the same height, same acceleration, same time to reached the ground and with the same initial velocity. According to the equations of motion of uniform acceleration, the a, v, u ,s, t will not be affected by the mass as all the equations need not to consider the mass.

Explanation for the wrong answer:
A. Gravitational force, W = mg
Since one ball is larger than the other, they have different masses and therefore the weights(Gravitational force acting on the balls) are different.

C. KE = (0.5) m v^2
Since the masses are different, according to the above equation, their KE are different.

D. PE = mgh
Since the masses are different, according to the above equation, their PE are different