This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Analytical Epidemiology, Subject name: Social & Preventive Medicine
Natural history of disease is best studied by - 
Select and explain. 
A. Cross-sectional study, B. Cohort study, C. Case contral study, D. Any of the above
B: Cohort study
Answer: B: Cohort study 
Explanation: Ans. is 'b' i.e., Cohort study o Natural history of disease is studied by longitudinal studies :o Among longitudinal studies cohort study is more useful for natural history of disease than case-control disease.