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': 'Angle at gingival bevel in class II inlay cavity \nSelect and explain. \nA. 30°, B. 10°, C. 5°, D. 50°', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]