This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: parasitology, Subject name: Microbiology
[{'content': 'HIV patient presented with diarrhea. On stool examination, following acid fast organisms was seen. What is the drug of choice in this patient \nSelect and explain. \nA. Nitazoxanide, B. Primaquine, C. Niclosamide, D. TMP-SMX', 'role': 'user'}, {'content': 'Answer: A \nExplanation: * HIV patient with diarrhea showing acid fast organisms shows that organism may be: * Cryptosporidium parvum * Isospora belli * Cyclospora cayetanensis * Image shows 4-5um sized oocysts - suggestive of Cryptosporidium Ref: T.B of medical parasitology S.C.Parija 4th edition; pg num:- 151', 'role': 'assistant'}]