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': 'Preparation of shoulder in anterior tooth is done with: \nSelect and explain. \nA. Invested cone bur, B. Plain fissure bur, C. Cross cut fissure bur, D. End cutting bur', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]