This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
[{'content': 'Somatostatin is produced by \nSelect and explain. \nA. Alpha cells, B. Beta cells, C. Delta cells, D. PP cells', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Alpha cellsGlucagonBeta cellsInsulin, amylinDelta cellsSomatostatinPP cellsPancreatic polypeptideRef: Harrison 19e pg: 2403', 'role': 'assistant'}]