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
Resorption of thick margins resulting in plateau formation is called as 
Select and explain. 
A. Crater, B. Ledge, C. Lipping, D. Trauma from oclusion
B: Ledge
Answer: B: Ledge 
Explanation: None