This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Forensic Medicine
[{'content': 'Speed ball is - \nSelect and explain. \nA. Opioid + cocaine, B. Opioid + antihistaminic, C. Cocaine + alcohol, D. Cocaine + marijuana', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Opioid + cocaine o A combination of cocaine and heroin (opioid)taken by injection is called speed ball.", 'role': 'assistant'}]