This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'In a patient having HIV infections, oral ulcer is most commonly due to - \nSelect and explain. \nA. Candida, B. Cryptococcosis, C. Histoplasma, D. Trichophyton', 'role': 'user'}, {'content': "Answer: A \nExplanation: Mouth often involved in AIDS with hairy leukoplakia or Kaposi's sarcoma due to esophageal candidiasis It is also known as Oral thrush REF:ANANTHANARAYANAN TEXTBOOK OF MICROBIOLOGY 9EDITION PGNO.576", 'role': 'assistant'}]