Which fiber is strong, flexible, smooth and naturally shiny?

• A. Wool
• B. Textile fibers
• C. Silk
• D. Linen

Answer: (C)

The main idea here is understanding how a fiber’s structure gives it strength, flexibility, smoothness, and natural shine. Silk fits all of these characteristics tightly. Silkworms produce long, smooth fibers with a triangular cross-section that refracts light, giving a natural, soft shine. The protein fibroin that makes up silk fibers provides high tensile strength for a lightweight material, and the fibers bend easily without breaking, which explains its excellent flexibility and drape. The combination of a smooth surface and lustrous appearance is a hallmark of silk.

Wool, while strong and elastic, has a fuzzier, crimped surface and is not naturally shiny. Linen is strong and cool to the touch but tends to be crisper and more textured rather than smooth and lustrous. Textile fibers is a broad category that doesn’t specify a single fiber with these particular attributes.