Final answer:
Most rear end crashes are indeed caused by the vehicle in the back following too closely, which is true. This is because tailgating reduces the time available to react and stop to avoid a collision.
Step-by-step explanation:
The statement that most rear end crashes are caused by the vehicle in the back following too closely is True. Following too closely, often referred to as tailgating, does not provide the following driver with enough time to react and stop if the vehicle in front suddenly slows down or stops. This is supported by traffic safety research and is a common cause of rear end collisions, as it impairs the following driver's ability to respond to changes in the preceding vehicle's speed.