Which of the following accurately describes the Materials Highway as seen in The Story of Stuff?

What does the start look like

The answer is b on edgenuity

Gravity, from the center of mass of the box, extending downward normal force, from the floor under the box, extending upward, equal to gravity push force, acting at a point on the box, extending in the direction of motion friction, acting at any point on the box directly opposite the push, extending directly opposite to the motion

Cannot be determined because i dont  know this but i need the points