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
Most common cause of infection due to catheter in urinary tract ? 
Select and explain. 
A. E coli, B. Coagulase negative staphylococci, C. Staph aureus, D. Pseudomonas
A: E coli
Answer: A: E coli 
Explanation: Ans. is 'a' i.e., E coli "E coli cause 80% of acute UTI in patients without catheterization". "E. coil is the most common cause of catheter associated UTI too".