Which condition results when the body's immune system cannot effectively fight infection and protect the body from disease, and can be genetic or due to chemotherapy, radiation, or immunosuppressive drugs?

Which condition results when the body's immune system cannot effectively fight infection and protect the body from disease, and can be genetic or due to chemotherapy, radiation, or immunosuppressive drugs?

• A. Hay fever
• B. Systemic lupus erythematosus
• C. Rheumatoid arthritis
• D. Immunodeficiency diseases

Answer: (D)

The key idea here is when the immune system doesn’t work well enough to defend the body. Immunodeficiency means the immune response is weakened or absent, making infections more frequent and harder to control. This can be congenital (genetic) or acquired later in life, such as from chemotherapy, radiation, or immunosuppressive drugs. The other conditions are autoimmune or allergic disorders, where the immune system overreacts or targets the body’s own tissues or harmless substances, not a failure to defend against infections. So the best match is immunodeficiency diseases.

The key idea here is when the immune system doesn’t work well enough to defend the body. Immunodeficiency means the immune response is weakened or absent, making infections more frequent and harder to control. This can be congenital (genetic) or acquired later in life, such as from chemotherapy, radiation, or immunosuppressive drugs. The other conditions are autoimmune or allergic disorders, where the immune system overreacts or targets the body’s own tissues or harmless substances, not a failure to defend against infections. So the best match is immunodeficiency diseases.