17/57.
Since the deregulation of airlines, delays at the nation's increasingly busy airports have increased by 25 percent. To combat this problem, more of the takeoff and landing slots at the busiest airports must be allocated to commercial airlines.
Which of the following, if true, casts the most doubt on the effectiveness of the solution proposed above?
(A) The major causes of delays at the nation's busiest airports are bad weather and overtaxed air traffic control equipment.
(B) Since airline deregulation began, the number of airplanes in operation has increased by 25 percent.
(C) Over 60 percent of the takeoff and landing slots at the nation's busiest airports are reserved for commercial airlines.
(D) After a small midwestern airport doubled its allocation of takeoff and landing slots, the number of delays that were reported decreased by 50 percent.
(E) Since deregulation the average length of delay at the nation's busiest airports has doubled.
A correct, 我选的是C
A还是不太明白，是说题目中的建议实际上隐含了假设就是造成airport忙的原因是commercial airlines. 则A用他因解释，因为天气状况才造成airport忙的。不知道现在想的对不对。有NN 帮忙解释一下吗？ | 
