Biofuels generally refer to solid, liquid or gaseous fuels extracted from biomass. Biomass refers to various organisms produced through photosynthesis using the atmosphere, water, land, etc. , that is, all living and growing organic substances. Including plants, animals and microorganisms. According to the above definitions, Which of the following are not classified as biofuels:. ['Vehicle ethanol after corn processing.', 'The fuel generated from genetically modified E. coli.', 'Biogas from anaerobic fermentation of crops.', 'Soy capable of refining biodiesel.']