Which among the following immune response is responsible for the graft rejection ?

Cell-mediated immune response.

The immune response responsible for graft rejection is primarily the Cell-mediated immune response.

When a graft or transplant is introduced into a recipient's body, the immune system recognizes it as foreign tissue. The cell-mediated immune response involves the activation of T lymphocytes (T cells), which play a significant role in recognizing and attacking foreign cells or tissues. In the case of graft rejection, T cells recognize the transplanted tissue as non-self and initiate an immune response to reject or attack the foreign graft.

While the humoral immune response, mediated by B cells and antibodies, can contribute to certain types of rejection, the cell-mediated immune response is the primary mechanism responsible for graft rejection. Autoimmune response, on the other hand, involves the immune system mistakenly attacking the body's own tissues and is not directly related to graft rejection.