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
In case of retreatment which is ideal for removal of G.P.? 
Select and explain. 
A. H-file, B. K-file, C. GT-file, D. Lentulospiral
A: H-file
Answer: A: H-file 
Explanation: None