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: Physiology
[{'content': 'Best stimulii for the secretion of secretin is \nSelect and explain. \nA. Protein, B. Food carbohydrate, C. Water, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Protein', 'role': 'assistant'}]