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
Ramping can be done for a 
Select and explain. 
A. one wall defect, B. two wall defect, C. three wall defect, D. four wall defect
A: one wall defect
Answer: A: one wall defect 
Explanation: None