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': "Which of the following is a reflex mediated by vagus? \nSelect and explain. \nA. Bile flow from liver, B. Pancreatic secretion of bicarbonate, C. Cephalic phase of gastric secretion, D. Mucous secretion from the Brunner's glands", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]