77. A certain mayor has proposed a fee of five dollars per day on private vehicles entering the city, claiming that the fee will alleviate the city’s traffic congestion. The mayor reasons that, since the fee will exceed the cost of round-trip bus fare from many nearby points, many people will switch from using their cars to using the bus.
Which of the following statements, if true, provides the best evidence that the mayor’s reasoning is flawed?
(A) Projected increases in the price of gasoline will increase the cost of taking a private vehicle into the city.
(B) The cost of parking fees already makes it considerably more expensive for most people to take a private vehicle into the city than to take a bus.
(C) Most of the people currently riding the bus do not own private vehicles.
(D) Many commuters opposing the mayor’s plan have indicated that they would rather endure traffic congestion than pay a five-dollar-per day fee.
(E) During the average workday, private vehicles owned and operated by people living within the city account for twenty percent of the city’s traffic congestion.

题目说，是5 dollars引诱了人们不开私家车而改去坐公车的。此题要求反对市长的推理。答案是B，这是一个他因法的削弱－－是因为停车费已经很贵了，所以人们选择坐公车。但我感觉好像AD都对。OG的解释没有看明白：
Choice A does not undermine the mayor’s view that the five-dollar fee will provide an incentive to switch to buses.
Choice D is inappropriate since many drivers not switching to buses is entirely consistent with many people making the switch.
我觉得，A说油价提高会导致开私家车费用提高，所以开私家车的人会switch to buses。
D说人们宁可去忍受交通堵塞，也不去在乎那5 dollars。
A和D都是分别说一个他因的解释，都说得通。

请大侠指正，AD错在哪里？

A and D support the reasoning of the mayor. it requires to points out his flaw.