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': 'Overall optimum degree of taper of tooth preparation for maxillary anterior tooth is: \nSelect and explain. \nA. 6 degrees, B. 10 degrees, C. 14 degrees, D. 19 degrees', 'role': 'user'}, {'content': 'Answer: B \nExplanation: For anterior preparations, 10 degree taper is recommended.\nFor cast preparations, 6 degree taper is optimum.\n\nRef: Stephen Rosenstiel, Martin Land, and Junhei Fujimoto, Contemporary Fixed Prosthodontics 5th Edition', 'role': 'assistant'}]