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': 'You are being asked to give your expert opinion as a toxicologist regarding an effective antidote for belladonna poisoning. Which of the following agents would you suggest? \nSelect and explain. \nA. Neostigmine, B. Physostigmine, C. Pilocarpine, D. Methacholine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]