Concept:Fermentation is an anaerobic process where enzymes from microorganisms break down sugars to produce alcohol and carbon dioxide.Explanation:In alcoholic fermentation, yeast and some bacteria convert sugars like glucose into ethanol (alcohol) and CO₂ without oxygen. The sugar molecules are the starting material, and alcohol is the main product. Yeast acts as a catalyst, not as a substance that gets converted. Option A is correct because sugar changes into alcohol during this process. Option B is wrong because yeast is not transformed into alcohol. Options C and D are incomplete: CO₂ is a byproduct, but the primary conversion is sugar into alcohol, not just into CO₂.Answer:A. Sugar into alcohol