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
Instruments used for removal of lingual shoulder and enlarge orifices of a root canal are 
Select and explain. 
A. Gates Glidden drills, B. Peeso reamers, C. Compactor, D. H File
A: Gates Glidden drills
Answer: A: Gates Glidden drills 
Explanation: None