Who is responsible for ensuring all passengers are properly restrained by a seatbelt?

The driver is responsible for ensuring that all passengers are properly restrained by a seatbelt because it is part of their duty to maintain safety within the vehicle. This responsibility stems from the fact that the driver is in control of the vehicle and should take necessary precautions to protect all occupants. In many jurisdictions, laws also specifically state that the driver can be held accountable for unrestrained passengers, particularly minors, which emphasizes the role of the driver in maintaining safety.

While passengers have a personal responsibility to wear their seatbelts, it's the driver who ultimately governs the vehicle's operation and can influence passenger behavior. The vehicle owner might have a role in ensuring the vehicle is equipped with functioning seatbelts, but they are not always the person operating the vehicle. Similarly, the insurance company does not bear responsibility for passenger safety in terms of compliance with seatbelt laws. Thus, the correct answer highlights the driver's legal and moral obligation to prioritize passenger safety.