Final answer:
Seatbelts offer the best protection in frontal crashes by restraining passengers and distributing forces, while airbags and crumple zones contribute by reducing the impact force through extending the time of impact.
Step-by-step explanation:
When considering which feature offers the best protection in frontal crashes, it is essential to understand the physics concept of impulse, which is the product of the net force and the duration over which the force acts. Seatbelts are critical safety features designed to restrain passengers and distribute the forces of a crash across some of the body's strongest regions. Airbags deploy upon impact, further protecting occupants by allowing the force to act over a longer period, thus reducing the impact force. Crumple zones in vehicles also play a crucial role in safety: by lengthening the time of impact during a crash, they reduce the force exerted on the passengers. Lastly, Anti-lock Brakes (ABS) help maintain control during braking but do not directly protect in the event of a collision. Considering the direct impact on passenger safety in the event of a frontal crash, seatbelts provide the best protection, working in conjunction with airbags and crumple zones to lessen overall injury.