What is the main purpose of seat belts?

The main purpose of seat belts is to protect occupants during a collision and reduce the risk of injury. Seat belts are designed to keep passengers securely in their seats, preventing them from being thrown around inside the vehicle or ejected from it in the event of an accident. They restrain the body's movement, allowing the vehicle's safety features—such as airbags and the overall design of the car—to work effectively.

The engineering behind seat belts is based on principles of physics; during a collision, the car comes to a sudden stop, and without a seat belt, the passenger's body would continue moving forward at the same speed. This forward momentum can lead to serious injuries. By wearing a seat belt, the forces experienced during a crash are distributed across the stronger parts of the body, significantly reducing the likelihood of severe injury or death.

While other options might touch upon aspects related to driving, such as comfort or vehicle security, they do not reflect the fundamental safety purpose of seat belts in automobile design.