Environmentalist: Pollution from gasoline burned by cars contributes to serious environmental problems. But the cost of these problems is not reflected in gasoline prices, and hence usually does not affect consumers' decisions about how much to drive. Heavier taxes on gasoline, however, would reflect this cost, and as a result consumers would pollute less.
 The statement 'Consumers would purchase less gasoline, on average, if the cost of the environmental problems to which pollution from driving contributes were fully reflected in the price of gasoline' most strongly supports which one of the following.