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
Incidence of disease among exposed divided that of non exposed is equal to - 
Select and explain. 
A. Relative risk, B. Attributable risk, C. Odd ratio, D. None of the above
A: Relative risk
Answer: A: Relative risk 
Explanation: Ans. is 'a' i.e., Relative risk RR =Incidence of disease among exposed----------------------------------Incidence of disease among nonexposed AR =Incidence of disease in exposed - Incidence of disease in unexposed--------------------------------------------------------Incidence of disease in exposedx 100