<prompt> Delayed tuberculin test response is due to-B lymphocytesT lymphocytesMonocytesHistiocytes  <response>: Tuberculin test is type IV hypersensitivity reaction. Delayed or cell mediated hypersensitivity is a cell mediated response. The antigen activates specifically sensitised CD4 CD8 T lymphocytes leading to the secretion of lymphokines and phagocyte accumulation. Reference : Anathanarayan panikers 9th edition, pg no: 162 p 