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': 'Chemicals used in root preparation are: \nSelect and explain. \nA. Citric acid, B. Fibronectin, C. Tetracycline, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]