Which of the following best describes AIDS?

• A. A disease that is due to a weakened immune system
• B. A disease caused by a virus
• C. A disease that is caused by bacteria
• D. A disease that is transmitted through water

Answer: (A)

AIDS is the advanced stage of HIV infection, defined by a severely weakened immune system. HIV destroys CD4+ T cells, so the body can’t mount effective defenses against infections and certain cancers. That immunodeficiency is what makes AIDS the correct description — a disease characterized by a compromised immune system and the resulting vulnerability to opportunistic infections.

Note: HIV is a virus, but AIDS isn’t described as a virus-caused disease; it’s the consequence of HIV‑related immune damage. It isn’t caused by bacteria, and it isn’t transmitted through water. Transmission occurs through certain body fluids, such as blood, semen, vaginal fluids, and breast milk.