Name one method of physical sterilization.

The correct method of physical sterilization in this context is steam sterilization. This technique utilizes high-pressure steam to kill microorganisms, including bacteria, viruses, and spores. Steam sterilization operates under the principle that the combination of heat and moisture works effectively against various pathogens, making it a widely accepted and reliable method for achieving sterility in medical instruments and supplies.

This process is usually carried out in an autoclave, where the steam penetrates the items being sterilized, raising their temperature to a level that effectively destroys microbial life. The use of steam is advantageous because it not only sterilizes but also is less harmful to materials compared to other methods, such as certain radiation or dry heat sterilization processes.

While chemical sterilization and radiation sterilization are methods used in sterilization, they rely on chemical agents or radiation instead of physical agents like heat and steam. Ultrasonic sterilization typically refers to the use of ultrasonic waves to clean items rather than to achieve sterilization through the physical killing of microbes. Therefore, steam sterilization stands out as the clear option for physical sterilization methods.