What is the purpose of a seatbelt?

The purpose of a seatbelt is primarily to keep occupants secure in their seats. When a vehicle is in motion, especially during sudden stops or collisions, a seatbelt restrains the occupants and prevents them from being thrown forward or ejected from the vehicle. This significantly reduces the risk of serious injury or fatality by ensuring that the individual remains in a controlled position within the vehicle.

While other options may contain elements that pertain to seatbelts, they do not address their fundamental safety function. For example, while it is true that seatbelts can influence the aesthetics of a car or may be required by law, these reasons are secondary compared to the crucial role a seatbelt plays in protecting the lives of vehicle occupants during travel. Thus, the correct answer emphasizes the main function of seatbelts in vehicular safety.