The correct statement in the context of a moving ball coming to a stop due to a nonzero net force is:
The net force causes a decrease in acceleration because without the force the ball's velocity would remain the same.
This statement captures the idea that the presence of a net force (in the opposite direction of the ball's motion) causes the ball to decelerate and eventually stop. Without that net force, the ball would continue moving at its initial velocity (due to Newton's first law of motion).