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
Denominator of positive predictive value is ? 
Select and explain. 
A. True positve + False positive, B. True positive + False negative, C. False positive + True negative, D. False positive + False negative
B: True positive + False negative
Answer: B: True positive + False negative 
Explanation: Ans. is 'b' i.e., True positive + False positive