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: Surgery
Which of the following technique can be used only in edentulous maxilla to treat oro-antral fistula? 
Select and explain. 
A. Rehrmann Flap, B. Ashley Flap, C. Bridge Flap, D. Burger Flap
C: Bridge Flap
Answer: C: Bridge Flap 
Explanation: None