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
Increasing the etching concentration 
Select and explain. 
A. Increases the micropores formed, B. Increases the length of the enamel tags, C. Causes precipitation of phosphates, D. increases the bond strength
C: Causes precipitation of phosphates
Answer: C: Causes precipitation of phosphates 
Explanation: None