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
[{'content': 'Resorption of thick margins resulting in plateau formation is called as \nSelect and explain. \nA. Crater, B. Ledge, C. Lipping, D. Trauma from oclusion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]