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 cavosurface angle for inlay cavity preparation \nSelect and explain. \nA. 90 degree, B. 150 degree, C. Less than 90 degree, D. 180 degree', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]