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 thickness of thin rubber dam is: \nSelect and explain. \nA. 0.002 inch, B. 0.004 inch, C. 0.006 inch, D. 0.2 inch', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]