Technology that enables drivers to pay tolls automatically,

Technology that enables drivers to pay tolls automatically, using a small device mounted to their cars, has become increasingly popular. Economists compared the toll rates in places using automated collection with those that collect tolls manually. They found that automated collection is associated with toll rate increases 20 to 40 percent higher than in places using manual collection. This difference may be due to the costs associated with the technology. However, another study showed that manually collected tolls increased the least during election years, while automatic tolls showed no such pattern.

Which of the following hypotheses is best supported by the statements given?

(A) Despite lower increases, manual toll collection is much more expensive than is automated collection.
(B) Rates where tolls are manually collected are less politically motivated than rates where tolls are automatically collected.
(C) Politicians seeking reelection try to keep manually collected tolls low in order to garner favor with their constituents, while they do not make the same effort with automatically collected tolls.
(D) In the years following election years, manually collected tolls increase more than do automatically collected tolls.
(E) As voters grow accustomed to automatically collected tolls, they will associate those rates with their elected officials, so politicians seeking reelection will attempt to limit those rate increases, as well.