Carla pushes a toy car and lets it go. the toy car rolls and gradually comes to a stop. what would make the car stop?

a. a force must be applied to the car in the direction opposite to that in which it is moving.
b. a force must be applied pushing the car forward in the same direction as the moving car.
c. a force must be applied in a direction pushing the car upward to make the car stop.
d. a force must be applied in a direction pulling the car downward causing the car to stop.