A boy sitting in a rail road car throws a ball straight up into the air. The ball will fall back into his hands when the rail road car is a.moving at constant velocity b.accelerating forward while going around a curve of radius equal to the maximum height attained by the ball c.107 dynes d.accelerating forwardA block A is dropped down a smooth inclined plane, while another identical block B is released for free fall from the same height e.decelerating