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: Microbiology
Regarding Natural Killer Cell, all are true except? 
Select and explain. 
A. It is activated by IL-2, B. CD-56 positive, C. Antibody induced proliferation, D. Variant of large lymphocyte
C: Antibody induced proliferation
Answer: C: Antibody induced proliferation 
Explanation: Natural Killer Cells (or NK cells) are a type of cytotoxic lymphocyte critical to the innate immune  system.
NK cells play is analogous to that of cytotoxic T cells in the vertebrate adaptive immune response.  
CD 56 and CD 16 positive.
Special action against viruses and tumor cells.