Consider a car riding on a roller coaster that goes through various loops. Which of these are true of the forces acting on the car?

A. If the speed is constant, then the centripetal force is equal to the net force

B. The centripetal force is provided by a combination of the normal force and the gravitational force

C. The total force is equal to the normal force plus the gravitational force plus the centripetal force.

D. The vector for the gravitational force always opposes the normal force