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' is: 
Select and explain. 
A. Risk among exposed/Risk among non-exposed, B. Risk among exposed/Risk in total population, C. Risk among exposed/Risk among exposed-Risk in new exposed, D. None of the above
A: Risk among exposed/Risk among non-exposed
Answer: A: Risk among exposed/Risk among non-exposed 
Explanation: Risk among exposed/Risk among non-exposed