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 impression with the least dimensional change upon disinfection is 
Select and explain. 
A. Addition poly silicone, B. Agar-agar, C. Polysulphide, D. Polyether
A: Addition poly silicone
Answer: A: Addition poly silicone 
Explanation: None