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
Sterilising/disinfecting agents include all, except: 
Select and explain. 
A. Dry heat, B. Ethylene oxide, C. Ether, D. Alcohol
C: Ether
Answer: C: Ether 
Explanation: Sterilization is the process by which an article, surface or medium is freed of all living microorganisms either in vegetative or spore state.
Sterilization agents are :

Heat
Filtration
Ionizing radiations
Gases (ethylene oxide, formaldehyde gas)
Sterilant liquids

Disinfection means destruction or removal of all pathogenic organism, which are capable of producing the infection. Disinfecting agents are:

Alcohols (ethyl and isopropyl alcohol)
Dyes
Halogens (Iodine, chlorine)
Phenol derivatives (Hexachlorophene, Lysol, cresol)
Biguanides (Chlorhexidine)
Oxidising agents (KMnO4, H2O2)
Quarternary ammonium compounds (cetrimide)
Soaps
Acids
Aldehydes
Metallic salts

– Ether is used as anesthetic agent, not as disinfectant or sterilizing agent.