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
Heat labile instruments for use in surgical procedure can be best sterlized by : 
Select and explain. 
A. Absolute alcohol, B. Ultra violet rays, C. Chlorine releasing compounds, D. Ethylene oxide gas
D: Ethylene oxide gas
Answer: D: Ethylene oxide gas 
Explanation: “Heat sensitive articles may be sterilized at 55-60 0 C by ethylene oxide which kills bacteria, spores, viruses.”

It is highly penetrating and highly explosive.
CO2 or N2 decrease its explosive tendency and water vapour increase its efficacy.
It acts as alkylating agent.
It is specially used for sterlizing heart - lung machines, sutures, dental equipment, books, fabrics, plastic equipment, cardiac catheters, clothing, glass, plastics, metal and paper surfaces.
It is unsuitable for fumigating room since it is explosive.