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': "'D' cells of the pancreas secrete: \nSelect and explain. \nA. Insulin, B. Glucagon, C. Intestinal peptide, D. Somatostatin", 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Somatostatin', 'role': 'assistant'}]