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': 'A partial agonist at acetylcholine nicotinic receptors that can be used in smoking cessation programs is \nSelect and explain. \nA. Acamprosate, B. Varenicline, C. Buprenorphine, D. Nalbuphine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]