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. In order to reduce maintenance time, airline officials are considering using a new 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.

Which of the following, if true, is further evidence that using the film will help the airline officials achieve their goal?

(A) Unlike paint, the film gives a milky tone to certain colors.
(B) At the end of its useful life, the film can be removed much more quickly than paint can.
(C) The film can be applied only by technicians who have received special training.
(D) The metal exteriors of airplanes have to be protected from high temperatures and caustic chemicals such as exhaust gases.
(E) Even at speeds considerably higher than the normal speed of a passenger jet, the film remains securely attached.

Ans: B

Their goal is "reduce maintenance time", but I think removing film occured at the end of useful life is not relative to their goal.

Could you explain it?

if we take it for granted that the processes of painting the plane and applying the film are parallel - i.e., both of them need to be removed "at the end of their useful life" - then this choice represents an additional cost savings, because, prior to applying a new coat, they'll be able to strip off the film faster than they'll be able to strip off the paint.

i see your point, though; this is a potentially dangerous assumption.
still, the other four choices clearly have NOTHING to do with time efficiency and faster maintenance. choice (b) is the only one that's even tangentially related to that idea, so it's the winner almost by default.

remember, the question is not "which one of these is SOLID evidence?" it's just "which one is further evidence?"
therefore, frustratingly enough, if one choice is weak evidence, but all four of the other choices are clearly irrelevant, then the "weak evidence" choice wins.

might i be so rude as to ask which of the other answer choices you thought could have been possible?

I chose D. I think "protecting exteriors of airplanes" sounds relative to "reducing maintanence time". And I also made an assumption that plastic film protects exteriors of airplans, even though I still uncomfortable about "have to be protected".

you're missing the issue here, though.
the issue is not just protecting the exterior of the planes per se. rather, the issue is protecting the exterior of the planes better than paint does.

number one, this statement has nothing to do directly with maintenance time. it just doesn't; you have to make big assumptions to reach any connection between those two concepts.
number two, and even more importantly - even if there's a connection between protecting the planes' exterior and reducing maintenance time, this statement still doesn't have anything to do with the comparative maintenance time between the plastic and the paint. (this is the sole thesis of the argument: that the plastic will lead to less maintenance time than will the paint.) therefore, this statement is irrelevant no matter what assumptions you make.