In order to finance road repairs, the highway commision of a

In order to finance road repairs, the highway commision of a certain state is considering a 50 percent increase in the 10-cents-per-mile toll for vehicles using its toll highway. The highway commissioner claims that the toll increase will increase the annual revenue generated by the toll highway by atleast 50 percent per year.

Which of the following is an assumption on which the highway commisioner's claim depends?

(A) The amount of money required annually for road repairs will not increase from its current level.
(B) The total number of trips made on the toll highway per year will not decrease from its current level.
(C) The average length of the trip made on the toll highway will not decrease from its current level.
(D) The number of drivers who consistently avoid the highway tolls by using secondary roads will not increase from its current level.
(E) The total distance traveled by vehicles on the toll highway per year will not decrease from its current level.

Please explain.

Regards,
Brajesh