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 study of smoking as a cause of lung cancer, 90 cases were taken, 75 were smokers and among 100 controls 40 were smokers. Calculate the odds ratio ? \nSelect and explain. \nA. 2, B. 4.5, C. 7.5, D. 10', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., 7.5 Odds ratio is cross product of entries in the table. So, it is very impoant to make a correct table construct ? i) History of exposure (risk factor) is arranged on left column (row). ii) Disease is arranged on the top ? a) Cases in middle column (row) b) Controls in right column (row)", 'role': 'assistant'}]