This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 2, Subject name: Forensic Medicine
[{'content': 'All are cardiotoxic except \nSelect and explain. \nA. Aconite, B. Opium, C. Oleander, D. Nicotine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Opium is somniferous poison, not cardiotoxic poison. cardiotoxic poisons: Car- Cardiac D- Digitalis O- Oleander N- Nicotine A- Aconite Mnemonic: CAR DONA', 'role': 'assistant'}]