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: Pharmacology
[{'content': 'Somatostatin secreted by which type of cells in pancreas ? \nSelect and explain. \nA. Gamma cells, B. Delta cells, C. Alpha cells, D. Beta cells', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]