This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
All of the following statements regarding prevalence are true except- 
Select and explain. 
A. It is rate, B. It is propoion, C. Duration of disease effects prevalence, D. Numerator is a pa of denominator
A: It is rate
Answer: A: It is rate 
Explanation: Ref:Parks 23rd edition pg 61. Prevalence is a propoion with numerator being a pa of denominator. Prevalence refers specifically to all current cases (old and new) existing at a given point in time, or over a period of time in a given population.