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': 'P4 pf vagina during reproductive life is \nSelect and explain. \nA. Alkaline, B. Acidic, C. Neutral, D. Variable', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vaginal secretion is acidic during reproductive life which is oestrogen dependent, and inhibits growth of pathogenic organisms.', 'role': 'assistant'}]