Final answer:
ETO sterilization requires ethylene gas to sterilize heat-sensitive items and works effectively at low temperatures, with moisture enhancing its effectiveness.
Step-by-step explanation:
The necessary component for ETO sterilization to occur is d) Ethylene gas. Ethylene oxide is a type of alkylating agent used for gaseous sterilization, and it is effective at low temperatures, making it suitable for sterilizing heat-sensitive items. Unlike autoclaving, which requires high pressure and high temperature to sterilize, ETO sterilization essentially requires ethylene gas to carry out the sterilization process. However, moisture, although not as crucial as the ethylene gas itself, can enhance the effectiveness of ETO sterilization by improving the gas's penetration and reaction with microbial DNA.