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: Pathology
Which of the following causes the majority of UTI’s in hospitalized patients? 
Select and explain. 
A. Lack of fluid intake, B. Inadequate perineal care, C. Invasive procedures, D. Immunosuppression
C: Invasive procedures
Answer: C: Invasive procedures 
Explanation: Invasive procedures such as catheterization can introduce bacteria into the urinary tract. 
A lack of fluid intake could cause concentration of urine, but wouldn’t necessarily cause infection.