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': 'Instruments used for removal of lingual shoulder and enlarge orifices of a root canal are \nSelect and explain. \nA. Gates Glidden drills, B. Peeso reamers, C. Compactor, D. H File', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]