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: Social & Preventive Medicine
Most common nosocomial infection is 
Select and explain. 
A. Respiratory tract infection, B. Gastrointestinal tract infection, C. Urinary tract infection, D. Throat infection
C: Urinary tract infection
Answer: C: Urinary tract infection 
Explanation: None