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 a major contraindication to 
resection of crestal bone? 
Select and explain. 
A. Gingival recession, B. Post surgical infection, C. Removal of healthy bone, D. Weakening
D: Weakening
Answer: D: Weakening 
Explanation: None