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: Dental
[{'content': 'The last solution used in root canal treatment to avoid painful surgical emphysema before dressing is \nSelect and explain. \nA. Normal saline, B. EDTA, C. Hydrogen peroxide, D. Sodium hypochlorite', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]