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: Dental
Which of the following surgical procedure is carried out first: 
Select and explain. 
A. Mucogingival surgery, B. Gingivectomy, C. Flap surgery, D. Osseous recontouring
C: Flap surgery
Answer: C: Flap surgery 
Explanation: None