What is the purpose of a seatbelt?

The primary purpose of a seatbelt is to secure passengers in place during an accident. By keeping occupants firmly strapped in, seatbelts significantly reduce the risk of serious injury or death by preventing them from being ejected from the vehicle or colliding with interior parts during a crash. In the event of a sudden stop or impact, seatbelts distribute the force of the collision across the stronger parts of the body, such as the chest and pelvis, thus minimizing the chance of injury.

While other options might touch on related subjects, they do not address the fundamental safety aspect that seatbelts provide. For example, while comfort and posture are important for driving, they are not the main function of a seatbelt. Similarly, seatbelts do not have a role in preventing vehicle theft; their design and purpose are focused solely on passenger safety.