Airbags became mandatory in all cars in 1998 and it estimated that they have saved the lives of over 50,000 people in that time. The benefit of airbags is that they ____________.
a. Lengthen the time a person is brought to a stop in an accident
b. Shorten the time a person is brought to a stop in an accident
c. Increase the momentum of the person in an accident
d. Decrease the impulse of a person in an accident