This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Physiology
[{'content': 'Which inhibits gastric secretion? \nSelect and explain. \nA. Secretin, B. High gastric pH, C. Insulin, D. Calcium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A', 'role': 'assistant'}]