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 axiopulpal depth of the proximal box in class II cavity is \nSelect and explain. \nA. 0.2 to 0.8mm, B. 0.5 to 1mm, C. 1 to 2mm, D. 2 to 3mm', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]