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
Consider the following characteristics of vaginal discharge in bacterial vaginosis : 
Select and explain. 
A. Green and thick, B. pH < 4.5, C. Increase in number of lactobacilli, D. Whiff test positive
D: Whiff test positive
Answer: D: Whiff test positive 
Explanation: Whiff test positive