Which of the following is an example of a bodily fluid?

The selection of urine as an example of a bodily fluid is based on the definition of bodily fluids, which includes any liquid produced by the body's biological processes. Urine is a waste product filtered by the kidneys and excreted from the body, containing water, urea, and various salts and substances that have been processed by the body.

In contrast, air, dust, and food waste do not fit this definition. Air is a mixture of gases and does not originate from the body's biological functions. Dust is composed of fine particles and does not pertain to body functions whatsoever. Food waste, while it may relate to the digestive process, is not classified as a bodily fluid; it consists of leftover material after the body has absorbed nutrients and is eliminated through a different bodily process.