This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vigina, Subject name: Gynaecology & Obstetrics
6. Cause of acidic pH of vagina is due to? 
Select and explain. 
A. Doderlein Bacilli, B. Gardnerella, C. Mobilincus, D. Glycogen
A: Doderlein Bacilli
Answer: A: Doderlein Bacilli 
Explanation: Ans. (a) Doderlein BacilliRef: Shaw 13thed p. 125, Novak's Gynecology 12th ed p-192, Jeff coate 7ed p-27