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': 'The process of achieving limited removal of epithelial tissue in the sulcus while creating chamfer finish margin is called: \nSelect and explain. \nA. Rotary curettage, B. Mechanico surgical gingival retraction, C. Electro surgery, D. Periodontal curettage', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]