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 one of the following tooth brushing techniques is
most likely to clean the gingival sulcus? 
Select and explain. 
A. Bass method, B. Charter's method, C. Modified stillman's method, D. Rolling stroke method
A: Bass method
Answer: A: Bass method 
Explanation: None