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
The following structure represents which impression material? 
Select and explain. 
A. Polyether, B. Polysulfide, C. Condensation silicone, D. Addition silicone
B: Polysulfide
Answer: B: Polysulfide 
Explanation: None