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: Pathology
All of the following statements about NK cells are true except - 
Select and explain. 
A. They are derived from large granular cells, B. They comprise about 5% of human peripheral lymphoid cells, C. They are MHC restricted cytotoxic cells, D. They express IgG Fc receptors
C: They are MHC restricted cytotoxic cells
Answer: C: They are MHC restricted cytotoxic cells 
Explanation: Ans. is 'c' i.e., They are MHC restricted cytotoxic cells