This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'While analysis of data, allocation into similar groups is done to ensure- \nSelect and explain. \nA. Comparability, B. Accuracy, C. Validity, D. Sensitivity', 'role': 'user'}, {'content': "Answer: A \nExplanation: In a case-control study, the controls may differ from cases in a number of factors like age, sex, occupation. - it is necessary to ensure comparability between cases and controls. - this process is called matching. Reference: Park's textbook of preventive and social medicine, 23rd edition, pg no:72", 'role': 'assistant'}]