In terms of impulse and momentum, why do air bags in cars reduce the chances of injury in accidents?

A. Air bags shorten the time of contact between the car and person thereby reducing the force of contact
B. Air bags lengthen the time of contact between the car and person thereby reducing the force of contact
C. Air bags act to reduce the force of contact between the car and person, the time of contact does not matter
D. Air bags act to reflect the collision force back to the object the car struck (Newton's third law, equal and opposite reactions)