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
Maximum delay allowed to pour cast with Hydrocolloids impression material 
Select and explain. 
A. 15 min, B. 30 min, C. 45 min, D. 2 hours
B: 30 min
Answer: B: 30 min 
Explanation: Immediate pouring is required. Maximum 30 min can be there, stored at 100% relative humidity in 2% K2SO4 solution.