Because of the lack of a comprehensive rail system in the United States, shipping relies greatly on the trucking industry, and hence on diesel fuel. Diesel consumption is therefore a major issue to be addressed in regards to not only air quality but also American dependence on foreign sources of oil. One proposed solution involves biofuels, which produce cleaner emissions than fossil fuels, but the use of corn and soy, traditionally food stocks, for production of biofuels has sparked a high rate of inflation in food prices around the world. Algae have also been proposed as a possible solution to this problem. Because half of algae's weight is lipid oil, and extraction is a simple process, it could serve as a more efficient alternative to corn- and soy-based oils. Given the successful use of algae for fuel production, the US government should begin production of algae biofuel plants to offset the detrimental effects of diesel fuel consumption by the trucking industry.

Which of the following statements, if true, casts the most doubt on the conclusion that the government should begin production of algae biofuel plants?

(A) Oil prices have been rising at a steady rate for more than 10 years.
(B) The high cost of algae-based biofuels will discourage the trucking industry from embracing the new fuel.
(C) Increased domestic oil production would offset dependence on foreign oil and reduce prices.
(D) Many types of algae cannot be used for biofuel production.
(E) Many farmers strongly support the use of corn and soy biofuel's.