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
Most common cause of pyelonephritis in pregnancy- 
Select and explain. 
A. Pseudomonas, B. E coli, C. Proteus, D. Klebsiella
B: E coli
Answer: B: E coli 
Explanation: 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.