Which of the following does not present antigens:: (A) NK cells, (B) Dendritic cells, (C) Langerhans cells, (D) Macrophages
Answer is A. APC (Antigen-presenting cell): 

Most common APC → Immature dendritic cell.
The most potent stimulator of native T cell → Mature dendritic cell.
APCs are – Dendritic cells, Langerhan’s cells, B-cell.