The national infrastructure for airport runways and air traffic contro

This is a weaken question. It's best to fully digest the argument and then make a rough prediction of what a correct answer choice would look like prior to heading to the answer choices in strengthen/weaken critical reasoning questions. Here the argument states that the imposed fee will be unfair because all travelers will pay it but only the few travelers who utilize private planes will benefit from it. If we can find a reason why everyone will actually benefit from it, and not just those who utilize private planes, then that would effectively weaken this argument.

A - The existing infrastructure is not what is being discussed. The issue is that a fee is being imposed to pay for infrastructure expansion, so discussing the existing infrastructure on its own is not relevant.

B - Out of scope. The argument didn't say anything about this fee reducing overall air travel volume. It is very possible that everyone who utilizes air travel continues to do so, but only now they have to pay a fine that for many of them is not viewed as far.

C - This gets at our prediction, and is thus correct. If the expansion reduces flight delays by eliminating congestion, then probably many air travelers are going to benefit from this infrastructure expansion, not only the few people who utilize private planes.

D - Completely out of scope. Nobody's wealth is relevant here.

E - Saying that the fee will be large is out of scope. If anything this would seem to strengthen the argument if the fee ends up being substantial for normal travelers, but the magnitude of the fee is in reality out of scope. The issue is simply about whether other travelers having to pay the fee is fair, and it does not matter if the fee is $1,000,000 or $.01 per person.

I hope this helps!