Final answer:
Cotton pads should be stored in a closed container to ensure optimal hygiene by protecting them from dust, bacteria, and other contaminants.
Step-by-step explanation:
Cotton pads should be stored for optimal hygiene to maintain cleanliness and avoid contamination. The correct answer is a. In a closed container. This storage method protects the cotton pads from dust, bacteria, and other potential contaminants. Storing them exposed on a treatment table or scattered on a countertop exposes the pads to the environment, which could lead to contamination. An open basket, while tidier than leaving them scattered, still does not protect from airborne particles and bacteria.