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: Social & Preventive Medicine
[{'content': 'Chemical use in vaginal sponge is - \nSelect and explain. \nA. Ethynil estradiol, B. Progesterone, C. Mifepristone, D. Nonoxynol-9', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is `d' i.e., Non - oxynol - 9 Vaginal sponge It is marketed in USA under the trade name TODAY. o It is small polyurethane foam sponge saturated with spermicide, nanoxynol-9. o The failure rate :- i) Parous women --> 20 to 40 per 100 women years. ii) Nulliparous women --> 9 to 20 per 100 women years.", 'role': 'assistant'}]