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: Unknown
[{'content': 'At mu receptor, buprenorphine is - \nSelect and explain. \nA. Partial agonist, B. Partial antagonist, C. Complete agonist, D. Complete antagonist', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Partial agonist .", 'role': 'assistant'}]