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
A disease whose etiology is not known, the first step in the formation of hypothesis will be ? 
Select and explain. 
A. Cross sectional study, B. Descriptive epidemiology, C. Case control study, D. Coho study
B: Descriptive epidemiology
Answer: B: Descriptive epidemiology 
Explanation: Ans. is 'b' i.e., Descriptive epidemiology Descriptive epidemiology is the first phase of epidemilogical investigation.