According to Newton’s first law of motion, which of the following objects will change its motion?
A.A train pulling on another train, each with the same amount of force.
B.A bike rider on a smooth and level road, pedaling at a constant rate.
C.A chair sitting on the floor with balanced forces acting in opposite directions.
D.A ball rolling across the floor with friction acting in the opposite direction.
A ball rolling across the floor with friction acting in the opposite direction.