This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Medicine
[{'content': 'A patient with human immunodeficiency virus (HIV) infection has progressed to developing AIDS (clinical category C). Which of the following conditions is considered an AIDS-defining illness? \nSelect and explain. \nA. antibodies to HIV, B. palpable lymphadenopathy, C. Kaposi sarcoma, D. oral candidiasis (thrush)', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The current case definition of AIDS in a patient with HIV infection is done by symptoms and CD4+ T-lymphocyte cell count. Any category C symptoms (e.g., cervical cancer, mycobacterium avium infection, CMV, retinitis, Kaposi sarcoma, etc.) indicates frank AIDS as does a CD4+ T-cell count <200/mL regardless of symptoms. Shingles and thrush are category B symptoms.', 'role': 'assistant'}]