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 one of the following is the role of barrier membrane in GTR? 
Select and explain. 
A. To help overall healing, B. Prevention of epithelial migration, C. To stop bleeding, D. To prevent the underlying tissues from the infection
B: Prevention of epithelial migration
Answer: B: Prevention of epithelial migration 
Explanation: None