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: Medicine
[{'content': 'Most common cause of acute UTI: \nSelect and explain. \nA. E.coli, B. Klebsiella, C. Strep. faecalis, D. Staph. saprophyticus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: → Acute uncomplicated UTI:-\u202f\xa0\n\nEscherichia coli– cause about\u202f80% of UTI.\xa0\n\n\xa0\n→\u202f20% UTI caused by:-\xa0\n\nGram negative enteric bacilli –\u202fKlebsiella proteus.\xa0\nGram positive cocci –\u202fStreptococcus faecalis.\xa0\nStaphylococcus saprophyticus -\u202frestricted to infection in young sexually active women.', 'role': 'assistant'}]