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': "Which of the following is a foldable rubber dam frame? \nSelect and explain. \nA. Starlite visi frame, B. Young's metal frame, C. Nygaard-Ostby, D. Le cadre articule", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]