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
Pre-requisite for plaque formation 
Select and explain. 
A. Pellicle, B. glycoprotein, C. mucopoly saccharide, D. dextran
A: Pellicle
Answer: A: Pellicle 
Explanation: None