The correct statement about the relationship between the net force and the ball's movement is:
The net force causes a decrease in acceleration because without the force the ball's velocity would remain the same.
This is because according to Newton's second law of motion (F = ma), a net force acting on an object results in a change in its motion. In this case, the ball is experiencing a net force that is opposite to its direction of motion, leading to a decrease in its velocity until it comes to a stop. Without this net force, the ball would continue moving at a constant velocity.