Which of these is NOT a natural fiber commonly used in textiles?

Polyester is not a natural fiber; it is a synthetic fiber. Natural fibers are derived from plants or animals, while synthetic fibers are produced through chemical processes.

Jute is a plant-based fiber commonly used for making burlap and other textiles. Silk is produced by silkworms, making it an animal-based fiber. Wool, sourced from sheep, is another example of an animal fiber. While all of these fibers are valued for their distinct properties and uses in textiles, polyester stands apart as a man-made fiber created from petrochemicals. This fundamental difference characterizes polyester and solidifies its categorization as a synthetic fiber, distinguishing it from the natural fibers listed in the other options.