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': 'Round tapered blank of Stainless steel is used and multiaxis grinding process is done for following \nSelect and explain. \nA. K file, B. Reamer, C. Hedstroem File, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]