Certain politicians in the country of Birangi argue that a 50 percent tax on new automobiles would halt the rapid increase of automobiles on Birangi' s roads and thereby slow the deterioration of Birangi' s air quality. Although most experts agree that such a tax would result in fewer Birangians buying new vehicles and gradually reduce the number of automobiles on Birangi' s roads, they contend that it would have little impact on Birangi' s air-quality problem. Which of the following, if true in Birangi, would most strongly support the experts' contention about the effect of the proposed automobile tax on Birangi's air-quality problem? ['Automobiles become less fuel efficient and ttherefore contribute more to air pollution as they age.', 'Currently, the sales tax on new tax on new automobiles is considerably lower than 50 percent.', 'Some of the proceeds from the new tax would go toward expanding the nonpolluting commuter rail system.', 'The scrapping of automobiles causes insignificant amounts of air pollution.']