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
Which is best material for RPD impression 
Select and explain. 
A. Impression plaster, B. Irreversible hydrocolloid, C. Reversible hydrocolloid, D. None of the above
B: Irreversible hydrocolloid
Answer: B: Irreversible hydrocolloid 
Explanation: None