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': 'D cells of Islet of Langerhans of pancreas secrete? \nSelect and explain. \nA. Insulin, B. Glucagon, C. Gastrin, D. Somatostatin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D SomatostatinRef: Ganong, 25th ed. pg. 154Somatostatin is found in the D cells of pancreatic islets. It inhibits the secretion of insulin, glucagon, and pancreatic polypeptide and may act locally within the pancreatic islets in a paracrine fashion.', 'role': 'assistant'}]