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 most mucostatic impression material is 
Select and explain. 
A. Thin mix of plaster of paris, B. Zinc oxide eugenol impression paste, C. Free flowing wax, D. Reversible hydrocolloids
A: Thin mix of plaster of paris
Answer: A: Thin mix of plaster of paris 
Explanation: Impression plaster is a β-calcium sulfate hemihydrate used at a water/powder ratio of approximately 0.5 to 0.6. Its fluidity makes it suitable for making impressions of soft tissues in the uncompressed state, a characteristic of mucostatic impression material.
Rest all options are mucocompressive impression materials.
Ref: Phillips 12edition page no 177