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': 'Methadone is used to treat withdrawal symptoms of: PGI 12; NEET 13 \nSelect and explain. \nA. Cocaine, B. Heroin, C. Amphetamine, D. Barbiturate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Heroin', 'role': 'assistant'}]