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
Secondary impression with ZoE needed how much spacer thickness in tray? 
Select and explain. 
A. 0.2 mm, B. 1.0 mm, C. 1.5 mm, D. 2.0 mm
A: 0.2 mm
Answer: A: 0.2 mm 
Explanation: Due to minimal viscosity of Impression plaster and ZoE paste they do not need any spacer in custom tray (Means best option will be 0.0mm).