Numerous opportunistic diseases can affect individuals with the following conditions.

Explanation

Among the given options, the correct answer is d. AIDS. Measles, influenza, and hepatitis A can temporarily weaken the immune system, increasing susceptibility to other infections, but they are not classified as opportunistic infections. In contrast, AIDS (Acquired Immunodeficiency Syndrome), caused by HIV, leads to a profound loss of CD4⁺ T cells and severe immunodeficiency. This immunosuppressed state is specifically characterized by the occurrence of opportunistic infections such as tuberculosis, pneumonia, candidiasis, and other fungal, bacterial, and viral diseases. Thus, unlike measles, influenza, and hepatitis A, AIDS is directly associated with opportunistic infections due to its defining immune system damage.