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
The normal pH of the saliva is about 
Select and explain. 
A. 5.5, B. 9.5, C. 7.5, D. 8.5
C: 7.5
Answer: C: 7.5 
Explanation: None