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
The principal problem with tuberosity reduction is: 
Select and explain. 
A. Poor access, B. Formation of oro-antral fistula, C. Infection, D. Damage to posterior superior alveolar nerve
B: Formation of oro-antral fistula
Answer: B: Formation of oro-antral fistula 
Explanation: None