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
Which of the following cell does not have cytotoxic activity ? 
Select and explain. 
A. NK cells, B. Cytotoxic T-cells, C. Helper T-cells, D. Antibody dependent cells
C: Helper T-cells
Answer: C: Helper T-cells 
Explanation: Ans. is 'c' i.e.,Helper T-cells