The correct response that demonstrates Newton's third law of motion 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 response accurately describes Newton's third law, which states that for every action, there is an equal and opposite reaction. When the two bumper cars collide, the force exerted by one car on the other results in both cars experiencing equal and opposite forces, causing them to move away from each other.