The correct response that illustrates Newton's third law of motion in the context of bumper cars at an amusement park is:
"If two bumper cars collide with a certain force, then they will move away from each other in opposite directions with the same force."
This reflects the principle that for every action, there is an equal and opposite reaction, meaning the force exerted by one bumper car on the other is met with an equal force in the opposite direction.