Understanding the argument -
When an airplane is taken out of service for maintenance, it is often repainted as well, and during the repainting no other maintenance work can be done on the plane. - Fact
In order to reduce maintenance time, airline officials are considering using a new nontoxic plastic film instead of paint. - Conclusion.
Goal - To reduce the maintenance time.
Plan - Use nontoxic plastic film instead of paint.
The film takes just as long to apply as paint does, but many other maintenance tasks can be carried out at the same time. - Fact. Supporting premise.
Option Elimination - Strengthen the plan to help achieve the goal, which is "To reduce maintenance time."
(A) Unlike paint, the film gives a milky tone to certain colors. - Out of scope.
(B) At the end of its useful life, the film can be removed much more quickly than paint can. - If the film can be removed more quickly then its a dual advantage to the "reduce the maintenance time." ok.
(C) The film can be applied only by technicians who have received special training. - Weakener.
(D) The metal exteriors of airplanes have to be protected from high temperatures and caustic chemicals such as exhaust gases. - Out of scope.
(E) Even at speeds considerably higher than the normal speed of a passenger jet, the film remains securely attached. - It's a good advantage for the film, but our scope here is to ensure that the plan will meet the goal, which is "To reduce maintenance time." Does this help reduce the maintenance time? No. Out of scope.