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
The term TUG BACK is used to indicate 
Select and explain. 
A. Good fit of accessory gutta-percha point at the apical third, B. Good fit of master gutta-percha point at the apical third, C. Good fit of accessory cone in the main body of the canal, D. Good fit of the initial file at the apical third
B: Good fit of master gutta-percha point at the apical third
Answer: B: Good fit of master gutta-percha point at the apical third 
Explanation: None