Beat The GMAT a GMAT & MBA community

In the nation of partoria, large trucks currently account for 6 percent of miles driven on partoria's roads but are involved in 12 percent of all highway fatalities. The very largest trucks those with three trailers had less than a third of the accident rate of single and double trailer trucks. Clearly, therefore, one way for partoria to reduce highway deaths would be to reduce shippers to increase their use of triple trucks.

which of the following, if true, Most seriously weakens the argument ?

A. No matter what changes partoria makes in the regulation of trucking, it will have to keep some smaller roads off limits to all of larger trucks.
B. so far only the best, most experienced drivers for Patorian trucking companies have been driving triple trailer trucks.
C. very few fatal collisions involving trucks in patoria are collisions between two trucks.
D. In patoria, the safety record of trucking industry as a whole has improbved slightly over the past ten years.
E. In patoria, the maximum legal payload of a trailer truck is less than three times the maximum legal payload of the largest of the single trailer trucks.

IMO: B