This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Physiology
[{'content': 'Delta cells of pancreas secretes \nSelect and explain. \nA. Glucagon, B. Insulin, C. Somatostatin, D. Pancreatic polypeptide', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) Somatostatin', 'role': 'assistant'}]