This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'The common causative agent in diarrhea in AIDS patients is - \nSelect and explain. \nA. Toxoplasma, B. Cryptosporidium, C. Salmonellae, D. Mycobacteria', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Cryptosporidium", 'role': 'assistant'}]