Which of the following most logically completes the passage?
In cars, airbags provide good protection for the chest and head, but little or no protection for legs. A study of injuries resulting from car accidents showed that a large proportion were caused by blows to the legs. Therefore, if airbags protected this area, the risk of serious injury in car accidents would be greatly reduced, especially since_______________ .
A. among the drivers included in the study's sample of injuries, only a very small proportion had been wearing an airbag at the time of accident.
B. even those drivers who drive cars with airbags have poor understanding of the degree and kind of protection that airbags afford.
C. an airbag that included protection for the legs would have to be somewhat larger and more expensive than current airbags.
D. although the bones in the legs are large, severe impacts in that area are very likely to cause serious injury, such as compound fracture.
E. drivers generally remain in their seat when they crash, which reduces the likelihood of severe impacts to the legs.