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': 'Instrument having Shank with alternating cutting edges \nSelect and explain. \nA. Real world endo, B. Endotech endo. instrument, C. RACE, D. K-6', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]