Final answer:
Most rear-end collisions are caused by the vehicle in the back following too closely.
Step-by-step explanation:
The statement, Most rear-end collisions are caused by the vehicle in the back following too closely, is True. Rear-end collisions typically occur when the vehicle following behind fails to maintain a safe distance and stops or slows down too late to avoid a collision. When a driver follows too closely, they have less time to react and stop in case the leading vehicle suddenly brakes or encounters an obstacle.