Final answer:
The correct temperature required during steam sterilization in an autoclave for 9-15 minutes to ensure the destruction of all microbes, including endospores, is 250°F (121°C). Autoclaves operate typically at 121 °C or 132 °C under elevated pressure, which is necessary for effective sterilization.
Step-by-step explanation:
The simplest explanation is that it is a highly effective method of sterilizing and disinfecting objects through the use of heat — in the form of steam — plus pressure and time. During steam sterilization for 9-15 minutes, the temperature must reach at least 250°F (121°C).
Autoclaves utilize moist-heat sterilization to achieve temperatures above the boiling point of water, ensuring the destruction of microbes and endospores. The standard operating temperatures for autoclaves are usually 121 °C or sometimes 132 °C, under a pressure of 15 to 20 psi. It's essential that the steam has direct contact with the materials being sterilized to ensure complete sterilization, especially since endospores such as those from C.
botulinum require a minimum temperature of 116 °C (240 °F) for destruction, which is well above boiling temperature and can only be achieved in the high-pressure environment of an autoclave. Therefore, the correct answer is D. 250°F (121°C).