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 surgical procedure of choice for skeletal class 2 malocclusion due to retrognathic Mandible is 
Select and explain. 
A. Le fort I osteotomy, B. Advancement genioplasty, C. BSSO set back of mandible, D. BSSO advancement of mandible
D: BSSO advancement of mandible
Answer: D: BSSO advancement of mandible 
Explanation: None