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 setting expansion of gypsum products can be reduced by: 
Select and explain. 
A. Increased spatulation, B. Adding potassium sulfate, C. Less water powder ratio, D. Allowing setting under water
B: Adding potassium sulfate
Answer: B: Adding potassium sulfate 
Explanation: None