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': 'Who introduced cocaine in psychiatry - \nSelect and explain. \nA. Freud, B. Jung, C. Milar, D. Stanley', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sigmund Freud studied about the effects of cocaine. It is also believed that he was addicted to cocaine for a long period.', 'role': 'assistant'}]