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
The flap technique procedure which does not increase the width of attached gingiva: 
Select and explain. 
A. Apically positioned flap, B. Undisplaced flap, C. Fenestration operation, D. Free gingival graft
B: Undisplaced flap
Answer: B: Undisplaced flap 
Explanation: None