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 is not a component of Apexum Device \nSelect and explain. \nA. NiTi Hollow tube, B. Precarved NiTi coarse ablator, C. Precarved NiTi Smooth ablator, D. Precarved NiTi Fine ablators', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]