Which statement indicates when a patient with HIV is considered to have progressed to AIDS?

A. Two or more opportunistic infections are diagnosed: While opportunistic infections are a hallmark of AIDS, the clinical definition usually requires specific "AIDS-defining illnesses" or a specific CD4 count. B. Kaposi sarcoma appears: Kaposi sarcoma is an AIDS-defining illness, but it is not the only way to determine progression; the CD4 threshold is the more universal laboratory marker. C. CD4 cell level drops to 200: According to the CDC, an HIV-positive individual is diagnosed with AIDS when their CD4+ T-lymphocyte count falls below 200 cells/mm3 or they develop an AIDS-defining clinical condition. D. Patient tested positive for ELISA: A positive ELISA indicates HIV infection, not the progression to the clinical stage of AIDS.