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 of the following is essentially an excisional procedure of the gingiva? 
Select and explain. 
A. Modified widman flap, B. Undisplaced flap, C. Apically displaced flap, D. Papilla preservation flap
B: Undisplaced flap
Answer: B: Undisplaced flap 
Explanation: None