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
[{'content': 'Consider the following characteristics of vaginal discharge in bacterial vaginosis : \nSelect and explain. \nA. Green and thick, B. pH < 4.5, C. Increase in number of lactobacilli, D. Whiff test positive', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Whiff test positive', 'role': 'assistant'}]