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
HTR polymer is 
Select and explain. 
A. Polyether, B. Polytmethymethacrylate, C. Silica, D. Hydroxyapatite
B: Polytmethymethacrylate
Answer: B: Polytmethymethacrylate 
Explanation: None