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: Surgery
Use of all the following significantly decreases airborne infection in operating room except ? 
Select and explain. 
A. Laminar air flow, B. Air-conditioning, C. Ultraviolet light, D. Microfilters
B: Air-conditioning
Answer: B: Air-conditioning 
Explanation: Ans. is 'b' i.e., Air-conditioning