Correct Answer: A region with low ozone concentrations in the atmosphere

Solution : The correct answer is (B) A region with low ozone concentrations in the atmosphere

The term "ozone hole" refers to a specific phenomenon where the concentration of ozone in a particular region of the Earth's atmosphere becomes significantly depleted. This depletion occurs primarily in the stratosphere, specifically in the ozone layer. The ozone layer is a region that contains a higher concentration of ozone molecules, which play a vital role in absorbing and blocking a portion of the sun's ultraviolet (UV) radiation.

The ozone hole is a result of human activities that release substances known as ozone-depleting substances (ODS), such as chlorofluorocarbons (CFCs) and halons. These substances, once released into the atmosphere, can reach the stratosphere and undergo chemical reactions that break down ozone molecules, leading to a reduction in ozone concentration.

The ozone hole is most pronounced over Antarctica, where extremely low ozone concentrations are observed during the Southern Hemisphere's spring season. However, similar but less severe ozone depletion can occur in other regions of the world. Efforts have been made globally to reduce and eliminate the production and use of ozone-depleting substances through international agreements like the Montreal Protocol to protect the ozone layer and prevent further depletion.