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': 'The age and sex structure of a population may be best described by a \nSelect and explain. \nA. Life table, B. corelation coefficient, C. Population pyramid, D. Bar chart', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The age and sex distribution of a population is best represented by population pyramid\nIn countries with high birth rates as ours, it is broad based conical pyramid because of high birth rate and tapering of population with increase in age.\nIn developed countries with low birth rate, the pyramid swells in the middle and is narrow at the base and is not so conical at the top. (dumb bell shaped).\n\nUtility of population pyramid \nShape of population pyramid indicates fertility pattern\n\nBroad base, Narrow top (upright triangle): High proportion of younger population (developing countries)\nBulge in Middle: High proportion of adults (developed countries)\n\nSpan (height) of population pyramid indicates life expectancy\n\nTaller pyramid: Higher life expectancy (developed countries)\nShorter pyramid: Lower life expectancy (developing countries)\n\nSymmetry of population pyramid indicates sex ratio\n\nSymmetric pyramid: ideal sex ratio ( developed countries)\nAsymmetric pyramid: unfavorable sex ratio <1000 (developing countries)', 'role': 'assistant'}]