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 pin used in pin restoration of a root canal treated tooth is: 
Select and explain. 
A. Self thread pin, B. Cemented pin, C. Frictional pin, D. Any of the above
B: Cemented pin
Answer: B: Cemented pin 
Explanation: None