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': "Macewan's sign is seen in: \nSelect and explain. \nA. Cyanide poisoning, B. Alcoholism, C. Lead, D. Arsenic poison", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Alcoholism', 'role': 'assistant'}]