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
__________ is helpful in making radicular access after entry: 
Select and explain. 
A. Gates glidden drill, B. K-File, C. K-reamer, D. Round bur
A: Gates glidden drill
Answer: A: Gates glidden drill 
Explanation: None