Which of the following is NOT considered a natural carpet fiber?

The correct answer is olefin, as it is a synthetic fiber rather than a natural one. While cotton, silk, and wool are derived from natural sources—cotton from the cotton plant, silk from silkworms, and wool from sheep—olefin is manufactured from polymer resins. This distinction is significant because natural fibers typically possess qualities such as breathability, moisture absorbency, and biodegradability that synthetic fibers do not necessarily have. Synthetic fibers like olefin are often created to enhance durability and stain resistance but lack the organic characteristics of natural materials, making them a distinct category in flooring and textile applications.