14. A recent survey of all auto accident victims in laceName w:st="on">DolelaceName> laceType w:st="on">CountylaceType> found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.
The conclusion above is not properly drawn unless which of the following is true?
(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B) Considerably more than 20 percent of drivers and front-seat passengers in laceName w:st="on">DolelaceName> laceType w:st="on">CountylaceType> always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.(A)
(E) Most of the auto accidents reported to police in laceName w:st="on">DolelaceName> County do not involve any serious injury.
请问这道题考的是什么? 做题的时候我总不能做杂那里算吧