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
A screening test has 90% sensitivity and 90% specificity. Diseased population is 10% What is PPV ? 
Select and explain. 
A. PPV 80%, B. PPV 85%, C. PPV 90%, D. PPV 95%
C: PPV 90%
Answer: C: PPV 90% 
Explanation: Sensitivity = 90%
Specificity = 90%
Prevalence = 10%
(i) Formula for PPV according to Bayes Theorem,