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 association between disease & risk factor in a case control study is studied by - \nSelect and explain. \nA. Relative role, B. Attributable role, C. Population attributable role, D. Odds ratio', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]