Answer:
b. normal bacteria in the vagina are replaced by an overgrowth of other bacterial forms.
Explanation:
The vagina has a flora of microorganisms normally associated with it. These microorganisms normally do not cause disease (non-pathogenic). However, if there's an imbalance in their population (e.g vagina douching could affect the vagina flora), diseases such as vaginosis could occur due to overgrowth of disease causing organism.
Symptoms of Bacterial vaginosis are: itching, fishy smell, burning sensation when peeing, abnormal vaginal discharge (could be greenish, grey)