Which of the following should be washed before cooking or serving?

Washing fruits and vegetables before cooking or serving is essential to remove dirt, bacteria, and potential pesticide residues. In this context, choosing all of the options indicates an understanding of safe food handling practices.

Celery, like many leafy vegetables, can harbor dirt and pathogens in its crevices, making it important to wash thoroughly to ensure it's safe to consume.

Apples have a skin that can trap pesticides and germs, which are eliminated by rinsing the surface under running water, even if they are to be peeled afterward.

Broccoli, being a cruciferous vegetable, can also collect soil and microorganisms in its florets, highlighting the need for washing before it is cooked or eaten raw.

By selecting all of the options, it emphasizes the importance of washing a variety of produce before consumption to promote food safety. This practice not only helps in eliminating harmful contaminants but also ensures that the food retains its freshness and flavor when served.