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 fue] 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 _______.

Inferences:
They have compared cars fueled with methanol vs cars fueled with gasoline.
The main criteria for their comparison is the emission amount of pollution such as carbon monoxide and harmful hydrocarbons.
The statement agrees that Methanol powered cars produce higher formaldehyde emission but less atmospheric formaldehyde than gasoline cars.
This passage is all based on the chemistry and reaction of chemicals that produce the un-desired results.

(A) compared to carbon monoxide and some hydrocarbons produced by gasoline-powered cars, formaldehyde pollution is not a serious threat to the environment

In the passage it has been written “harmful” formaldehyde pollution. So this sentence does not make any sense. Even if this was reversed, still this logic would not make sense as cars producing the emission is based on their chemical reactions and not on opinions.

(B) the technical difficulties involved in mass-producing methanol-powered cars will prevent them from seriously competing with gasoline-powered cars for several years

The methanol-powered car is able to produce less atmospheric formaldehyde than gasoline powered cars because of their chemical reaction rather than their ability to produce a certain type of car.

(C) gasoline-powered cars are required by United States law to be equipped with catalytic converters that reduce emissions of many pollutants

This answer choice, answer the question “ What does United States law states for the cars with gasoline?” It is not answering why methanol is producing less pollutants than gasoline equipped cars.

(D) measuring a car's emissions is generally an accurate method of assessing that car's contribution to atmospheric pollution

This answer choice is justifying the results that whatever results they have got from their research is true. But it does not answer why?

(E) most formaldehyde pollution generated by gasoline-powered cars results from the photochemical conversion of hydrocarbon emissions into formaldehyde in the atmosphere.

Correct. Both the cars are producing pollutants but gasoline is producing more than methanol because of their chemical composition and not the opinions, law or other factors.