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 procedures can be used to treat an oro-antral fistula resulting from posterior surgery: (Or) Oro-antral fistula in maxillary 3rd molar region is best/commonly treated by 
Select and explain. 
A. Buccal mucoperiosteal flap, B. Palatal mucoperiosteal flap, C. Bridge flap, D. Palatal island flap
D: Palatal island flap
Answer: D: Palatal island flap 
Explanation: None