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
GTR is related to 
Select and explain. 
A. Gingivoplasty, B. Frenectomy, C. Mucogingival surgery, D. Gingivectomy
C: Mucogingival surgery
Answer: C: Mucogingival surgery 
Explanation: None