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
Most common form of disinfection of alginate impression material is 
Select and explain. 
A. Spraying 1% sodium hypochlorite, B. Spraying 5% sodium hypochlorite, C. Immersing in 1% sodium hypochlorite, D. Immersing in 5% sodium hypochlorite
A: Spraying 1% sodium hypochlorite
Answer: A: Spraying 1% sodium hypochlorite 
Explanation: The  current  protocol  for  disinfecting  hydrocolloid impressions recommended by the Centers for Disease Control and Prevention is to use household bleach (1-to-10 dilution), iodophors, or synthetic phenols as disinfectants. 
Guide for selection of Appropriate Disinfection Method for Impressions Transported to a Dental Laboratory