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?

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.

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.

我选e,因为private vehicles 只占traffic congestion的20%，所以限制private vehicles并不能解决根本问题。而答案选b,是因为停车费已经很高了，5块钱对车主根本构不成影响吗？如果这样理解的话，那这两个选项好像都对亚！

你们是怎么理解的？