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: Unknown
[{'content': 'To achieve a net reproduction rate (NRR) of 1, the couple protection rate (CPR) should be: \nSelect and explain. \nA. 20%, B. 30%, C. 40%, D. 60%', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ref. Foundations of Community medicine. Page. 113\n\xa0\nCouple Protection Rate (CPR)\n• It is an indicator of the prevalence of contraceptive practice in the community\n• Definition: the percentage of eligible couples effectively protected against childbirth by one or the other approved methods of family planning\n– Sterilization\n– IUD\n– Condom\n– OCP’s\n• NRR = 1 can be achieved only if the CPR > 60%', 'role': 'assistant'}]