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': 'Case control study is a type of- \nSelect and explain. \nA. Descriptive epidemiological study, B. Analytical study, C. Longitudinal study, D. Experimental epidemiological study', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Analytical studies include: Ecological or correlational-with populations as unit of study Cross sectional or prevalence-with individuals as unit of study Case control or case reference-with individual as unit of study Coho or followup-with individual as unit of study.(refer pg no:62 park 23rd edition)', 'role': 'assistant'}]