Final answer:
The correct answer to the student's question is 'a. Drying the surface.' This is the final step in the cleaning and sanitizing process, which aims to minimize microbial presence to safe levels, not necessarily achieve sterilization, on items such as dishes in a commercial dishwasher or surfaces in medical settings.
Step-by-step explanation:
The four steps in the cleaning and sanitizing process include cleaning the surface, rinsing the surface, sanitizing the surface, and drying the surface. This sequence is essential for minimizing the presence of microorganisms to levels safe for public health. For example, in food service settings like with commercial dishwashers, high temperatures are used during the washing and drying phases to effectively sanitize dishes. Similarly, chemical disinfectants are used to clean nonliving surfaces in medical laboratories and bathrooms, aiming not to sterilize, but to sufficiently reduce microbial presence.
Disinfection inactivates most microbes on a surface but does not achieve sterilization, as some microbes, such as endospores, can survive. Therefore, basic procedures such as handwashing follow specific steps outlined by the CDC for effective decontamination, which also includes thorough drying. In the context of routine cleaning and sanitizing practices, drying is the proper final step after sanitizing a surface.