All of these are antigen presenting cells (APC's)except -a) T cellsb) B cellsc) Fibroblastsd) Dendritic cellse) Langerhans cells
High-Yield Explanation
T cells cannot be activated by soluble antigens.
Therefore, presentation of processed antigen by antigen presenting cells is required for activation of T cell.
The initial step in immune response (whether humoral or cellular) is phagocytosis of the antigen by antigen presenting cells.
These antigen presenting cells process and present the antigen to T cells.
These activated T cells then interact with B cells (in humoral immunity) or with other T cells (in cell mediated immune response)