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': 'What is the thickness of class II matrix band? \nSelect and explain. \nA. 0.002 inches, B. 0.002 mm, C. 0.02 inches, D. 0.02 mm', 'role': 'user'}, {'content': 'Answer: A \nExplanation: There are two types of bands:\n\nUncontoured bands\nPrecontoured bands\n\nUncontoured bands\nThese\xa0are available in two thicknesses:\n\n0.002 inch (0.05 mm)\n0.0015 inch (0.038 mm)\n\nSturdevants operative dentistry south asian edition page 204', 'role': 'assistant'}]