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': 'Which of the following burs is used for developing\nchamfer margins? \nSelect and explain. \nA. Flat ended, tapered diamond cylinder, B. Round ended, tapered diamond cylinder, C. Twelve fluted carbide burs, D. End cutting burs', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]