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': 'All of the following statements concerning methods limiting family size, are true, except : \nSelect and explain. \nA. Women who do not breastfeed are much more likely to become pregnant than those who do, B. Globally the number of tubectomies far exceeds the number of vasectomies, C. The barrier methods (condoms and diaphragms) are perhaps the most effective at limiting family size, D. All anovulatory drugs are paicularly likely to cause effects in women over 35 years of age and women who smoke', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The barrier methods (condoms and diaphragms) are perhaps the most effective at limiting family size', 'role': 'assistant'}]