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: Forensic Medicine
[{'content': 'The active principle \nSelect and explain. \nA. Nicotine, B. Nerin, C. Abrine, D. Pilocarpine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. b. Nerin', 'role': 'assistant'}]