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
Specificity of a screening test measures aEUR' 
Select and explain. 
A. True positives, B. False positives, C. False negatives, D. True negatives
D: True negatives
Answer: D: True negatives 
Explanation: True negatives Repeat from May 06 Sensitivity is the ability of test to identify correctly all those who have the disease, i.e, 'true positives'. Specificity is the ability of a test to identify correctly those who do not have the disease, i.e. 'true negatives'.