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: Pathology
Ammonia causes 
Select and explain. 
A. Increase in plaque formation, B. Increase in calculus formation, C. Decrease in plaque formation, D. Causes precipitation of salivary proteins
C: Decrease in plaque formation
Answer: C: Decrease in plaque formation 
Explanation: None