This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
Fiber optic instruments like endoscopes should be disinfected by 
Select and explain. 
A. Formaldehyde, B. Cetrimide, C. Gamma radiation, D. Glutaraldehyde
D: Glutaraldehyde
Answer: D: Glutaraldehyde 
Explanation: 2% Glutaraldehyde for 20 minutes is active against bacteria, viruses and fungi. Latest 0.5% Ohophthaldehyde is used with 5min Contact period. Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 33