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 crown of an RC treated tooth is fractured near the gingival margin. The coronal end of the silver cone used in filling that canal is visible at that level. Treatment is: 
Select and explain. 
A. To prepare post space alongside the silver cone using burs and Peso reamers, B. To grind away the coronal part of silver cone using round burs or end cutting burs, C. To remove the silver cone and re-treat the canal using a gutta-percha; and then to create the needed post space, D. To remove the silver cone, notch it, coat it with a freshly mixed sealer replace it in the canal and twist off the coronal segment
C: To remove the silver cone and re-treat the canal using a gutta-percha; and then to create the needed post space
Answer: C: To remove the silver cone and re-treat the canal using a gutta-percha; and then to create the needed post space 
Explanation: None