This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Screening for Disease, Subject name: Social & Preventive Medicine
Specificity measures:(1997) 
Select and explain. 
A. True negatives, B. False positives, C. True positives, D. None of the above
A: True negatives
Answer: A: True negatives 
Explanation: Ans: aRef: Park, 17th ed, p. 112 & 18,h ed, p. 117