This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Enterobecteriaceae, Subject name: Microbiology
[{'content': 'Most common cause of pyelonephritis in pregnancy- \nSelect and explain. \nA. Pseudomonas, B. E coli, C. Proteus, D. Klebsiella', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 6b' i.e., E coli o The most common infection in pregnant women is urinary tract infectiono Most common infecting organism is E coli, can cause cystitis and pyelonephritis.", 'role': 'assistant'}]