The correct response is:
The force of his hand pushes up on the apple with equal magnitude to the force of gravity, which pulls down on the apple. The two forces are balanced, so the apple doesn't fall.
In this scenario, the upward force exerted by the boy's hand on the apple is equal to the downward force of gravity acting on the apple. When these two forces are equal in magnitude and opposite in direction, they are said to be balanced, which is why the apple does not fall.