6.A small car collides with a large truck. Which one of the following statements is true?
(a)The magnitude of the force that the truck exerts on the car is greater than the magnitude of the force that the car exerts on the truck.
(b)The magnitude of the force that the truck   exerts on the car is smaller than the magnitude of the force that the car exerts on the truck.
(c)  The forces that the two vehicles exert on each other are equal in magnitude.
(d)The relationship between the forces that the two vehicles exert on each other depends on the vehicles’ masses.