Which of the Following Is a Conservative Force? (All Refer

Multiple Choice

Which of the following is a conservative force? (All refer to a car on a slope.)

A) The force you exert on the car pushing it uphill.
B) The force exerted by rain drops falling on the car.
C) The frictional force of the road on the car.
D) The gravitational force acting on the car.
E) The force you exert on the car (pushing it uphill) after it starts to slide downhill.