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: Psychiatry
[{'content': 'Smack is the "common" name for - \nSelect and explain. \nA. Heroin, B. Cocaine, C. Opium, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Smack is a street name for Heroin.', 'role': 'assistant'}]