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 is a mucogingival surgery \nSelect and explain. \nA. Free gingival graft, B. Widman flap, C. Gingivectomy, D. Gingivoplasty', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]