This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
The "risk of a disease" is measured by the - 
Select and explain. 
A. Prevalence rate, B. Incidence rate, C. Case fatality rate, D. Communicability rate
B: Incidence rate
Answer: B: Incidence rate 
Explanation: <p> Incidence rate measures population at risk. Reference:Park&;s textbook of preventive and social medicine,K.Park,23rd edition,page no:60. <\p>