What items are included in a vehicle's restraint system?

The vehicle's restraint system encompasses all safety features designed to protect occupants during a collision. This includes shoulder belts, which help secure passengers in place and reduce the risk of injury; airbags, which deploy upon impact to cushion and protect occupants; and head restraints, which are designed to limit head movement and prevent whiplash type injuries during rear-end collisions. Since each of these components plays a critical role in enhancing safety, the correct answer is that all of them are included in the vehicle's restraint system. By understanding how these elements work together, drivers can appreciate the importance of always using seat belts and ensuring that their vehicle's safety features are operational.