This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'The Ethyl alcohol (Ethanol) is more effective when mixed with water and used as: \nSelect and explain. \nA. 10 to 20 percent, B. 20 to 30 per cent, C. 40 to 50 per cent, D. 60 to 70 per cent', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]