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': "Knife used for gingivectomy is: \nSelect and explain. \nA. Kirkland, B. Orbans, C. Merifield, D. Burkett's", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]