Ketchup and mustard bottles are to be _____, _____, _____, and _____ at night.

The correct answer focuses on the essential procedures necessary for maintaining food safety and hygiene standards in the restaurant environment. The processes of washing, rinsing, sanitizing, and re-filling ensure that the condiment bottles are not only clean but also safe for use.

Washing removes food residues and contaminants, rinsing eliminates any soap or cleaning agents, sanitizing kills off harmful bacteria, and re-filling ensures that the condiments are available for the next service period. This set of procedures is critical for preventing foodborne illness and maintaining the overall quality of the food served, aligning with industry standards for cleanliness and safe food handling.

The other responses suggest different maintenance tasks, but they do not capture the specific health and safety focus required for condiment management in a food service setting.