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 is the preferred material for use to sharpen a dental instrument to be used for tooth preparation? \nSelect and explain. \nA. Arkansas stone, B. Silicon carbide, C. Aluminium oxide, D. Diamond', 'role': 'user'}, {'content': "Answer: A \nExplanation: Arkansas stone is a naturally occurring mineral containing microcrystalline quartz and traditionally has been the preferred material for fine sharpening stones. Only a fine grit stone is suitable for the final sharpening of dental instruments to be used for tooth preparation.\nRef: Sturdevant's art and science of operative dentistry. 4th edition page 317", 'role': 'assistant'}]