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
Which of the following is first formed after tooth brushing 
Select and explain. 
A. Materia alba, B. Plaque, C. Pellicle, D. Calculus
C: Pellicle
Answer: C: Pellicle 
Explanation: None