The author most likely uses the word however in order to
Incorrect.
[[snippet]]Although we know that American discount airlines was successful where other airlines were not, this is not the function of the word however. In this context, however contrasts the success of American discount airlines with the means by which that success was achieved.
Good job!
[[snippet]]Since American discount airlines used means that could logically be expected to be displeasing to customers, their success is somewhat of a surprise.
Incorrect.
[[snippet]]Although the frugality of American discount airlines is the reason for their success, this is not the function of the word however in this context. The word however implies a relationship of opposition (rather than one of cause and effect) between American discount airlines' success and the means by which this success was achieved.
Incorrect.
[[snippet]]The author does not question the success of American discount airlines, although she or he does use the word however to denote that they achieved this success in an unusual way.
Incorrect.
[[snippet]]The passage implies that American discount airlines' success comes directly from their extra charges for services, even though this fact may be slightly surprising.