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': 'Framingham hea study is? \nSelect and explain. \nA. Case-control study, B. Coho study, C. Cross-sectional study, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is b i.e., Coho study Example of coho sutdies 1) Framingham hea study is a classical example of coho sutdy. 2) Smoking and lung cancer study. 3) Oral contraceptives and health study.', 'role': 'assistant'}]