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': 'For cast restorations the cavity wall should have a taper of \nSelect and explain. \nA. 30-45 degree, B. 5-10 degree, C. 2-5 degree, D. none of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]