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
In tight contacts, the best rubber dam material type is: 
Select and explain. 
A. Thin, B. Medium, C. Heavy, D. Extra Heavy
A: Thin
Answer: A: Thin 
Explanation: The thinner material has the advantage of passing through the contacts easier, which is particularly helpful when contacts are tight.