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
Biobrane is a commercially available: 
Select and explain. 
A. Root matrix protein, B. Biodegradable membrane, C. Bone graft material, D. Non-bone graft material
B: Biodegradable membrane
Answer: B: Biodegradable membrane 
Explanation: None