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': 'Denominator age group for calculation of dependency ratio is \nSelect and explain. \nA. 0-5 years, B. 5-15 years, C. 65 years and above, D. 15-65 years', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]