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
Generally recommended rubber dam is 
Select and explain. 
A. Dark, B. Heavy, C. 6x6 inches, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Generally, dark, heavy, 6 X 6 inch sheets are recommended