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
What treatment should not be required for the patient with grade II furcation involvement? 
Select and explain. 
A. Furcation plasty, B. Tunnel preparation, C. GTR, D. None
B: Tunnel preparation
Answer: B: Tunnel preparation 
Explanation: None