D. When bumper cars collide, one car will transfer its force to the other, and then they will bounce apart.
Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. In the case of bumper cars, when two cars collide, the force exerted by one car on the other is equal in magnitude but opposite in direction to the force exerted by the second car on the first one. This means that the force experienced by each car is the same, but in opposite directions. As a result of this exchange of forces, both cars will bounce apart from each other.