What is necessary regarding the safety belts of the vehicle?

The safety belts of the vehicle are a critical component of passenger and driver safety. Ensuring that they are functioning properly is essential for several reasons. Properly functioning safety belts are designed to restrain occupants in the event of a sudden stop or collision, significantly reducing the risk of injury or fatality.

When safety belts are in good working order, they will lock correctly and hold occupants in place, which is vital for their protection. The safety equipment must meet regulatory standards and be regularly checked to ensure effectiveness.

In contrast, options emphasizing that safety belts can be worn, are optional, or should be missing do not align with the principles of vehicle safety. Wearing them is indeed always encouraged for safety, but it is critical they are functioning properly to provide any benefit. Therefore, the only acceptable answer underscores the necessity of the safety belts being in optimal condition for them to fulfill their protective role.