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
[{'content': 'Which of the following surgical procedure is carried out first: \nSelect and explain. \nA. Mucogingival surgery, B. Gingivectomy, C. Flap surgery, D. Osseous recontouring', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]