Which of the following is considered an active restraint system?

An active restraint system is designed to actively protect occupants in the event of a collision by functioning during the crash. Seat and shoulder belts are considered active restraint systems because they are designed to secure the occupants in their seats, preventing them from being ejected or impacting the interior of the vehicle during a crash. They work by physically restraining the movement of the occupant when a sudden stop occurs.

Other choices, while important for vehicle safety, do not qualify as active restraint systems. Door impact beams are structural components that add strength to the vehicle's doors and protect against side impacts, but they do not actively restrain occupants. Interior lighting enhances visibility inside the vehicle, contributing to safety, but it does not restrain occupants. Airbags, while classified as passive restraint systems, deploy automatically during a collision to provide additional protection but do not engage until an accident occurs. Thus, seat and shoulder belts stand out as the active components designed to secure occupants during the driver's maneuvers and collision events.