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
All of the following are resorbable Guided Tissue Regeneration (GTR) except? 
Select and explain. 
A. Poly lactic acid, B. Poly galactic acid, C. Polylactic acid, polyglycolic acid, and trimethylene carbonate, D. PTFE
D: PTFE
Answer: D: PTFE 
Explanation: None