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
Dentin conditioner has the following function. 
Select and explain. 
A. Removes smear layer, B. Increases surface energy of dentin, C. Forms a thin resin layer over exposed collagen fibrils, D. Helps in bonding with composite
A: Removes smear layer
Answer: A: Removes smear layer 
Explanation: None