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: Pharmacology
[{'content': 'A newborn developed respiratory depression in a postoperative ward. It can result from the use of ? \nSelect and explain. \nA. Opioid, B. Propofol, C. Furosemide, D. Heparin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]