Which of the following diseases is not due to autoimmunity?
rheumatic fever
systemic lupus erythematosus
diabetes mellitus
hiv/aids

HIV/AIDS

Explanation:

Autoimmunity is the failure in a functional division of the immune system called self-tolerance, which results in immune responses against the body's own cells and tissues. Any disease that results from this type of response is called autoimmune disease. Examples of autoimmune diseases include rheumatic fever, systemic lupus erythematosus and diabetes mellitus.

HIV/AIDS is not an autoimmune disease, ie it is not related to autoimmunity.

AIDS, or Acquired Immunodeficiency Syndrome, is an infectious disease caused by the HIV (Human Immunodeficiency Virus), which leads to progressive loss of immunity. The disease - actually a syndrome - is characterized by a set of signs and symptoms resulting from the drop in the rate of CD4 lymphocytes, very important cells in the body's immune defense. The more the disease progresses, the more the immune system is compromised and, consequently, the carrier's ability to defend itself against infections.

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the answer to your question is:

c. complementary base-pairing