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: Gynaecology & Obstetrics
The pH of vagina in adult women is : 
Select and explain. 
A. 4.5, B. 6.5, C. 7.5, D. 7
A: 4.5
Answer: A: 4.5 
Explanation: 4.5