This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cells and Tissues of Immune System, Subject name: Pathology
NK cell CD marker is - 
Select and explain. 
A. 16, B. 60, C. 32, D. 25
A: 16
Answer: A: 16 
Explanation: Ans. is 'a' i.e., 16 o Two cell surface molecules, CD 16 and CD56, are widely used to identify* NK cells.