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
Before pouring an elastic impression, it is washed with slurry of water and stone to: 
Select and explain. 
A. Increase gel strength, B. Prevent syneresis, C. Prevent distortion, D. Wash off saliva on impression
D: Wash off saliva on impression
Answer: D: Wash off saliva on impression 
Explanation: None