C
Which of the following, if true, provides the most logical completion of the passage below? Cars fueled by methanol have a much lower level of emissions of pollutants such as carbon monoxide and environmentally harmful hydrocarbons than gasoline-fueled cars do. Methanol fuel does produce somewhat higher formaldehyde emissions than gasoline does. Nevertheless, a methanol-powered car actually produces less atmospheric formaldehyde pollution than a comparable gasoline-powered car, because .
A: compared to carbon monoxide and some hydrocarbons produced by gasoline-powered cars, formaldehyde pollution is not a serious threat to the environment
B: measuring a car's emissions is generally an accurate method of assessing that car's contribution to atmospheric pollution
C: most formaldehyde pollution generated by gasoline-powered cars results from the photo-chemical conversion of hydrocarbon emissions into formaldehyde in the atmosphere
D: gasoline-powered cars are required by United States law to be equipped with catalytic converters that reduce emissions of many pollutants