Correct answer: A). Ethanol
Bio-ethanol is an alcohol which is produced by the process of fermentation of crops. It is mainly produced by the fermentation of carbohydrates such as starch, which is found in sugarcane, sweet potato, corn etc.
It is also produced from cellulose biomass, which is derived from the non-food source like grass and trees.
It is produced through a biological process like anaerobic digestion, rather than geological process, which is used for the formation of fossil fuel like coal, petroleum.