Which statement best describes the industrial production method for ethanol?

• A. The reaction is fast and produces pure ethanol; the process is continuous and easy to scale up
• B. The reaction is slow and yields impure ethanol
• C. It requires no energy
• D. It relies on biological fermentation only

Answer: (A)

Industrial ethanol is produced mainly by fermentation of sugars using yeast, giving ethanol and carbon dioxide. In modern plants this fermentation happens in large vessels and is run continuously, which allows huge volumes to be produced and makes it easy to scale up. The ethanol produced from fermentation is not pure; it comes as an aqueous mixture and must be purified by distillation, which requires energy. So the best description among the options is that the process is continuous and easy to scale up, with purification steps needed to obtain ethanol.