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
Which of the following is radiopaque 
Select and explain. 
A. polysulphide, B. polyether, C. addition silicone, D. condensation silicone
A: polysulphide
Answer: A: polysulphide 
Explanation: None