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 in negative predictive value ? 
Select and explain. 
A. True positive + false positive, B. False negative + true positive, C. True negative + false positive, D. True negative + false negative
D: True negative + false negative
Answer: D: True negative + false negative 
Explanation: Ans. is 'd' i.e., True negative + false negative