If highways were restricted to cars and only those trucks with capacity of less than 8 tons, most of the truck traffic would be forced to run outside highways. Such a reduction in the amount of truck traffic would reduce the risk of collisions on highways. The conclusion drawn in the first sentence depends on which of the following assumptions?

A

The roads outside highway would be as convenient as highway for most drivers of trucks..

B

Most of the roads outside highways are not ready to handle truck traffic.

C

Most trucks that are currently running in highway have a capacity of more than 8 tons.

D

Cars are at greater risk of being involved in collisions than are trucks.