Transplantation of tissues/organs fails often due to non-acceptance by the patient's body. Which type of immune-response is responsible for such rejections?

Transplantation of tissues/organs faces the risk of rejection as it is recognized by the immune cells as non-self. The cell-mediated immune response is mainly involved in the rejection of the transplanted organs. The cell-mediated immune response mainly involves T cells which release cytokines in response to foreign objects. So, the correct answer is option A (Cell-mediated immune response).