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': "Magnan's phenomenon occurs in addiction of: \nSelect and explain. \nA. Alcohol, B. Cocaine, C. LSD, D. Opiates", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cocaine', 'role': 'assistant'}]