What is the leading cause of rear-end collisions?

Answer: C — Following too close behind another vehicle

The leading cause of rear-end collisions is following too close behind another vehicle. When a driver maintains an inadequate following distance, they reduce their ability to react to the vehicles ahead of them. This diminished reaction time can lead to a situation where the driver cannot stop in time if the vehicle in front suddenly slows down or stops. A safe following distance allows for ample time to react and brake, preventing a collision. In contrast, factors like improper brakes, high speed, and poor visibility may contribute to collisions, but they are not as consistently significant in the context of rear-end accidents. Following too closely directly impacts the ability to maintain safe spacing between vehicles, leading to the majority of rear-end incidents on the road.