Answer:
The best answer to the question: In what frame of reference would you be at rest while riding in a car, would be, indeed, D: the others in the car.
Explanation:
The reason for this being the correct answer comes mostly from the way that our brains perceive movement, or rest, depending on the motion, or state of movement, of others and of things. In this case, we are being to ask when we would perceive ourselves to be in a state of rest while being inside a moving vehicle, relative to other subjects and objects around. Since the car is moving, if the person looks out the window towards people on the streets, or a child pulling a wagon, or a bridge over a highway, the perception will be that I am moving, relative to the others, and therefore, I am not at rest. But in the moving vehicle, with others in the same state as I am, those people are static and so am I, and therefore I can assume that in this frame of reference, I am at rest while riding a car.
