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': 'Dentin Protection during cavity restoration is most\nimportant when the "remaining dentin thickness" is: \nSelect and explain. \nA. 1 — 2mm, B. 1.5 mm, C. 0.5 — 1mm, D. 0.5 mm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]