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': 'In NiTi rotary electric handpiece, rotation should be \nSelect and explain. \nA. 350-450, B. 250-300, C. 150-300, D. 100-150', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]