Final answer:
The correct answer to the student's question is that drain pipes subject to condensation over food storage in food-handling establishments shall be insulated to prevent contamination.
Step-by-step explanation:
The question relates to standards in food-handling establishments, particularly concerning the maintenance of drainage pipes. When dealing with drain pipes that are subject to condensation, especially those positioned over areas where food is stored, it is essential to insulate them to prevent condensation from dripping onto the food products. Therefore, the correct answer is A. Insulated. Insulation helps to maintain a consistent temperature in the pipes, thus reducing the likelihood of warm air coming into contact with cold surfaces and creating condensation that could lead to potential contamination of food items.