B. explain why it is more difficult to move an object at rest, than to keep an object moving
with uniform motion.

The reason is that the value of static friction between two contact surfaces is always greater than that of the kinetic friction between the same surfaces.

Explanation:

When a body is at rest on another body, the two surfaces exert a force called static friction that prevents the surfaces from sliding.

When one of the body is in motion, the two contact surfaces exert a force between them in the direction opposite to the direction of motion is called kinetic friction. It opposes the motion of the body.

The kinetic friction acts on the surfaces only when there is a motion associated with the surface with respect to the other.

The equation for static and kinetic friction is

                                      F = μₓ · η

Both static and kinetic forces have the same dimension. Only they differ is in the value of the coefficient of friction.

On analyzing the friction between two surfaces, the static friction of the two contact surfaces is always greater than that of their kinetic friction.

Hence, it is more difficult to move an object at rest, than to keep an object moving with uniform motion.

answer and explanation;

i think the answer is a, hope this : )