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': 'Statistical method of calculating death rate among two population with different age groups- \nSelect and explain. \nA. Crude death rate, B. Standardized death rate, C. Case fatality rate, D. Age specific death rate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Age adjustment or age standardization removes the confounding effect of different age structures of two different population and yields a single standardized rate, by which the mortality experience can be compared directly.', 'role': 'assistant'}]