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 function of the following armamentarium? \nSelect and explain. \nA. Field isolation, B. Dental extraction, C. Crimping of stainless steel crown, D. Orthodontic wire bending', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The figure shows rubber dam, which is used for isolation in oral cavity.\nIt was invented\xa0by S.C Barnum – 1864.\nIt has following parts:\n\nSheet\nRubber Dam Frame\nRubber Dam Clamp/Retainer\nRubber Dam Punch\nRubber Dam Forceps\nRubber Dam Lubricant\nRubber Dam Napkin\nAnchors', 'role': 'assistant'}]