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
A split thickness flap is indicated when: 
Select and explain. 
A. Osseous craters are present, B. Fenestrations and Dehiscence are suspected, C. Buttressing bone formation is present, D. Three walled osseous defects are encountered
B: Fenestrations and Dehiscence are suspected
Answer: B: Fenestrations and Dehiscence are suspected 
Explanation: None