This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Screening, Subject name: Social & Preventive Medicine
Denominator of positive predictive value is 
Select and explain. 
A. True positive + 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: .predictive value of a positive test is calculated as true positive divided by the sum of true positive and false positive expressed in percentage ref:park&;s textbook ,22 nd edition,pg no 130