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
If the prevalence of a disease in a population increases, the predictive value of a positive test ? 
Select and explain. 
A. Increases, B. Decreases, C. Remains constant, D. Becomes compromised
A: Increases
Answer: A: Increases 
Explanation: Ans. is 'a' i.e., Increases