What class of drugs is used to prevent organ rejection post-transplantation?

The correct choice is the class of drugs known as immunosuppressants. These agents are specifically designed to inhibit the immune response, which is crucial for preventing the rejection of transplanted organs. In a transplant scenario, the recipient's immune system may recognize the new organ as foreign and mount an attack against it. Immunosuppressants work by dampening this immune response, thereby reducing the likelihood of rejection and helping to ensure the transplant's success.

While corticosteroids can play a role in immunosuppression by reducing inflammation and altering immune responses, they do not encompass the full spectrum of immunosuppressive therapies used specifically for organ transplantation. Corticosteroids are often used in conjunction with other immunosuppressants but do not cover all aspects of preventing organ rejection on their own.

Anti-allergic agents are not involved in transplant procedures and primarily address allergic reactions rather than the suppression of immune responses related to organ transplants. Organ transplant agents is not a recognized category within pharmacology; rather, the drugs used in organ transplantation are classified as immunosuppressants.

Thus, the focus on immunosuppressants is important for understanding how the body can accept a foreign organ and the potential complications that can arise post-transplant.