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
[{'content': "Coho study is associated with: March 2010 \nSelect and explain. \nA. Prevalence, B. Odd's ratio, C. Relative risk, D. Exposure rates", 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. C: Relative riskOdd's ratio can be derived from a case control study, which is a measure of the strength of the association between risk factor and outcome.", 'role': 'assistant'}]