This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Classification, Coho Study, Subject name: Social & Preventive Medicine
In a coho study conducted, out of those exposed to risk factor 10 are diseased and out of those non - exposed to risk factor only 5 are diseased. What is the Relative risk? 
Select and explain. 
A. 1.33, B. 2, C. 0.5, D. 50
B: 2
Answer: B: 2 
Explanation: Relative risk = Incidence among exposed / incidence among non - exposed Incidence among exposed is 10, Incidence among non - exposed is 5 Thus, relative risk is 10/5 = 2 Relative risk 2 implies that association is present; and risk of development of disease among exposed is twice as common as compared to non - exposed.