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': 'Generally recommended rubber dam is \nSelect and explain. \nA. Dark, B. Heavy, C. 6x6 inches, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Generally, dark, heavy, 6 X 6 inch sheets are recommended', 'role': 'assistant'}]