I think the answer is E.
I did a very similar question today in PR's Verbal Bin3.
A. The reason why airlines are doing well is because of an alternative cause ie. companies refunding their money, not because of the travelers having enough money.
B. If the reason people are spending on flight tickets is because they have no other option (limited no. of choices, and increased costs by all airlines), it does not support the given reason of people spending money just because they have it, but because they don't have an option. Given the option, they probably wouldn't spend so much on it. I hope this makes sense!?
C. If people are finding ways to save money through shorter vacations & cheaper hotels, they probably do not have "more money to spend on
vacations than they did five years ago". This also weakens the argument.
D. Again, the reason people opt for the quicker, yet more expensive mode of transport (flights) is because the alternative is too time-consuming, NOT because they have
more money to spend.
E. How an airline would do depends on income from 2 segments: international (in this case, transatlantic) and domestic. If intl. flights just got more expensive, using the simple supply-demand theory, demand should go down. However, if the domestic airline segment has seen an increase in passengers, it means that the business from domestic segment could be so large that overall, airline companies are doing better. Why are the number of domestic passengers increasing? Because people are now taking vacations to locations within the country? But how does that imply that they have more money? Is this the right answer just because it does NOT weaken the argument?
So I started off assuming E was right...but, when I really started to question it, I ended up eliminating all the options?! Oh man...help!!!
Btw, what's the OA???