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 reason to repeat impression is? 
Select and explain. 
A. Improper positioning of tray, B. Too Less or excess material, C. Voids that are irreparable, D. Improper mixing
A: Improper positioning of tray
Answer: A: Improper positioning of tray 
Explanation: None