Admission Tests GRE Question Answer
A law has been proposed requiring the cargo boxes of trucks carrying gravel to be covered by a tarpaulin, because vehicles driving close behind open-topped gravel trucks can be damaged by gravel (lying off these trucks. The law is unlikely to substantially reduce such damage, however: flying gravel is much less likely to come from the cargo box itself than from the grooves of the tires, in which gravel can become wedged during loading.
Which of the following, if true, provides the strongest support for the argument given?