Final answer:
The motion of a ball rolling from rest down an inclined plane is that it will accelerate due to the gravitational force component acting along the slope.
Step-by-step explanation:
When a ball is allowed to roll from rest down an inclined plane, the correct motion of the ball is that it will accelerate as it moves down the plane. According to Newton's Second Law of Motion, the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. As the ball rolls down the incline, the component of gravitational force acting along the slope causes the ball to accelerate.
In the absence of opposing forces like friction or air resistance, the acceleration would be constant and directed down the incline. This is similar to an example where a ball rolls along the ground and friction acts opposite to its motion, but in the case of the inclined plane, friction could actually help the ball to roll without slipping, thus contributing to its rotational motion as well.