Correct Response: A. When a vehicle is involved in a crash, the vehicle and its passengers go from a high speed to a stop in a short amount of time. In order to bring a passenger to a stop, the seat belt must exert a force on the passenger over a duration of time. The average force required is inversely proportional to the length of time over which it is exerted. This means that, if the seat belt can bring the passenger to more gradual stop by stretching over a longer duration of time, a smaller average force will be required and the passenger is less likely to be harmed. The amount of stretch required would not be noticeable during everyday use. Hence, it would not result in accommodating a wider variety of body types (B) or providing greater comfort (C). It would not result in keeping the passenger's hips positioned more securely in the seat (D).
