The correct answer is Poles. Important Notes: • The ozone layer is a natural layer of gas in the upper atmosphere that protects humans and other living things from harmful ultraviolet (UV) radiation from the sun. • The ozone layer is typically thicker over the poles than over the equator. • The ozone layer exists in the stratosphere, a layer 10 to 50 km above the Earth’s surface. • The reasons for ozone depletion are a wide range of industrial and consumer applications, mainly refrigerators, air conditioners (hydrochlorofluorocarbons (HCFCs), chlorofluorocarbons (CFCs)), and fire extinguishers. • Ozone depletion is greatest at the South Pole (Antarctica). Explanation & Key Takeaways: • This severe depletion creates the so-called “ozone hole”. • The Negative Effects of the ozone hole are certain types of skin cancers, eye cataracts, and immune deficiency disorders. • UV rays also affect plant growth, reducing agricultural productivity. • The international community established the Montreal Protocol on ozone-depleting substances in 1987, to address the destruction of the ozone layer.