The problem cited involves a shift from using air transportation, which will involve paying the fees, to using automobiles, which does not involve paying the fees. So the solution will address this shift or its results.

(A) This will not address the shift or its results. If anything taking this course of action will exacerbate the problems.

(B) This is interesting and even tempting. The basic problem is pollution and use of vehicles that create the pollution. So if educating the public were effective in reducing that use, then the basic problem would be addressed, and the use of automobiles would be reduced. However the problem cited in the last sentence would not really be addressed. To the degree that people would still use polluting means of transportation, there would still be a shift from using air transportation and paying the fees to using automobiles and not paying the fees.

(C) Recommendations are a good first step, but setting recommendations would not affect the shift or its results.

(D) While in the long run doing this might somehow affect the dynamics of the situation, doing it does not clearly address the problem mentioned.

(E) Doing this would directly address both aspects of the problem, the shift and the results of the shift. If all forms of motorized transportation had associated pollution fees that were in direct proportion to the amount of pollution each form produces, then there would be no incentive to shift to avoid fees in such a way that pollution costs are not being paid. Meanwhile, whatever form of transportation people would choose, the people would pay fees that are appropriate given the pollution caused by that form.

The correct answer is E.