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
Epidemiological studies is carried for a period of - 
Select and explain. 
A. Incubation period, B. Twice the incubation period, C. Four times the incubation period, D. Half the incubation period
B: Twice the incubation period
Answer: B: Twice the incubation period 
Explanation: .epidemiological studies are usually employed for a period of twice the incubation period .it is done so so thzt most of the cases and associated risk factors are identified in such a way that it may help in the interpretation of data collected and thus the epidemiological analysis. ref:park&;s textbook,ed 22,pg no 67