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
Extraction of following isolated residual maxillary tooth offers the hazard of fracture of tuberosity: 
Select and explain. 
A. 3rd molar, B. 1st molar, C. 2nd molar, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Extraction of isolated residual maxillary molar offers the hazard of fracture of tuberosity or floor of the antrum.