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
A chest physician performs bronchoscopy in the procedure room of the out patient department. To make the instrument safe for use in the next patient waiting outside, the most appropriate method to disinfect the endoscope is by - 
Select and explain. 
A. 70% alcohol for 5 min, B. 2% glutaraldehyde for 20 min, C. 2% formaldehyde for 10 min, D. 1% sodium hypochlorite for 15 min
B: 2% glutaraldehyde for 20 min
Answer: B: 2% glutaraldehyde for 20 min 
Explanation: None