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
Relative risk 2 means ? 
Select and explain. 
A. Risk of developing disease is 2 times higher among nonexposed, B. 30% of disease among exposed is due to risk facter, C. 200% increase in risk of developing disease among exposed, D. Incidence rate is 2 times higher in exposed group than non-exposed
D: Incidence rate is 2 times higher in exposed group than non-exposed
Answer: D: Incidence rate is 2 times higher in exposed group than non-exposed 
Explanation: Ans. is 'd' i.e., Incidence rate is 2 times higher in exposed group than non-exposed It is very impoant to know the difference between relative risk and attributable risk.