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
Advantage of the submarginal falp for periradicular surgery is? 
Select and explain. 
A. Crestal bone less, B. Bleeding lees, C. Gingival shrinking less, D. Flap closure easy
A: Crestal bone less
Answer: A: Crestal bone less 
Explanation: None