abolition

A is the only one which says that airlines will still care about the safety...

will go for A..

Conclusion: Anxious to reduce fares in what has, as a result of deregulation, become a highly competitive market, airlines will be tempted to reduce costs by decreasing safety inspections and routine maintenance of aircraft.

(A)Consumers select an airline as much on the basis of its safety record as on the basis of its fares.[This choice clearly makes a pitch that price and safety plays an important role in consumer selection of the airlines. This choice weakens the argument. – hold it]
(B)There are a no of mechanical problem that cannot be detected in the routine inspection of aircraft.[Mechanical problem detection is out of scope – eliminate it]

(C)The amount of commercial air traffic has increased significantly since the regulation of airfares was abolished.[This has no direct impact on conclusion – eliminate it]

(D)The no of airline bankruptcies has increased since the regulation of airfares was abolished.
[Bankruptcies out of scope of the argument – eliminate it]
(E)When airfares were regulated, airlines were more inclined to invest in the development of new aircraft. [But nothing that links to safety concerns – eliminate it]

Answer: A