What is the main benefit of wearing a seatbelt while driving?

Answer: B — Reduces the risk of injury in an accident

Wearing a seatbelt while driving significantly reduces the risk of injury in an accident by securing the occupant in their seat and preventing them from being thrown forward or ejected from the vehicle during a collision. Seatbelts are designed to absorb the energy of a crash, helping to distribute the forces exerted on the body more evenly. This can lead to a substantial decrease in serious injuries and fatalities. In many accidents, the impact can cause severe harm to unbuckled occupants; however, wearing a seatbelt enhances safety by ensuring that individuals remain in their designated seating area, where airbags and other safety features can effectively protect them. The other options do not accurately represent the primary function of seatbelts. For instance, increasing car speed is not a benefit of seatbelt use; in fact, it can often lead to legal penalties. Similarly, using the radio is unrelated to the safety benefits provided by seatbelts, and while driving efficiency could have various influencing factors, seatbelts do not improve fuel efficiency directly. The focus on safety is where the importance of wearing a seatbelt truly lies.