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
Lefort 1 osteotomy essentially involves osteotomy of how many bones? 
Select and explain. 
A. 2, B. 3, C. 4, D. 5
D: 5
Answer: D: 5 
Explanation: None