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': 'In reproductive and child health programme,districts are divided on the basis of – \nSelect and explain. \nA. Crude birth rate & infant mortality rate, B. Crude birth rate & female literacy rate, C. Crude death rate & crude birth rate, D. Couple protection rate & infant mortality rate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]