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
Which of the following can be used as root canal filling materials 
Select and explain. 
A. Cements and plastic materials, B. G.P. Points, C. Silver points, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: None