Lupus, a condition in which the body attacks its own cells, is an example of an allergic disorder. an immunodeficiency disorder. a cancer of the immune system. an autoimmune disorder.

Correct D). An autoimmune disorder.

Lupus is an autoimmune disease that occurs in a condition when the body immune system attacks its own tissue and organs. It causes inflammation of the joints, it can also affect different body parts like skin, kidney, blood, brain heart and lung.

In the patient who suffers from lupus, in such patient, the antibodies are not able to distinguish between foreign cells and body's own cells. These auto-antibodies attack cells and tissues that causes inflammation.

Hence, the correct answer would be option D.