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 advantageous indication of acid etching is 
Select and explain. 
A. Decrease micro leakage, B. Decrease polymerization shrinkage, C. Decrease coefficient of thermal expansion, D. Decrease porosity in restorative material
A: Decrease micro leakage
Answer: A: Decrease micro leakage 
Explanation: None