Final answer:
The statement that best describes why textiles should not be exposed to ultraviolet rays is that UV rays fade and weaken the fabric, damaging the color and material's integrity due to their higher energy levels.
Step-by-step explanation:
The best description of why textiles should not be exposed to ultraviolet rays is C. Ultraviolet rays fade and weaken the fabric. This is because ultraviolet rays carry more energy than visible light, which can cause the breakdown of molecular bonds in the fabric, leading to both a fading of the colors and a weakening of the material. For instance, when the sun's rays hit textiles, dyes that absorb high-energy photons, such as blue and violet, are the last to fade. Yet dyes like red and green absorb the energetic blue and violet photons, causing the molecular structure of these dyes to degrade more quickly, resulting in fading and weakening of the fabric.
Dyes and DNA in fabrics are examples of complex molecules that are often weakly bound. These weak bonds are prone to being broken by high-energy UV rays. As a result, repeated exposure to UV light can degrade the fabric's strength and durability, along with causing colors to fade faster, especially reds, yellows, and greens.