What is the purpose of smart materials in sport clothing?

• A. To measure heart rate
• B. To change color in the rain
• C. To respond to sweat and temperature changes to improve comfort
• D. To reduce wind resistance

Answer: (C)

Smart materials in sport clothing are designed to sense what your body is feeling and the surrounding conditions and then respond to keep you comfortable. They can detect moisture from sweat and changes in temperature and adjust the fabric's behavior—for example, by increasing breathability or moving moisture away from the skin—so you stay cooler, drier, and more comfortable during activity. This adaptation to sweat and heat is why this option fits best.

Other ideas touch on different concepts: measuring heart rate would involve embedded sensors rather than the fabric actively changing itself to feel better; color-changing in rain is mainly a visual effect and not about comfort or performance; reducing wind resistance comes more from the garment’s shape and construction than from smart material responses to moisture or temperature.