Which statement describes ground-level ozone?

• A. It irritates lungs, damages plants, and is a major part of photochemical smog.
• B. It warms the stratosphere.
• C. It reduces visibility by absorbing rainfall.
• D. It has no health effects.

Answer: (A)

Ground-level ozone is a harmful pollutant formed near the earth’s surface when sunlight drives chemical reactions between nitrogen oxides and volatile organic compounds released by cars, power plants, and industry. This ozone is a key part of photochemical smog, which creates hazy, unhealthy air on sunny days. It irritates the lungs, causing coughing, throat irritation, and can worsen asthma, especially in children and people with respiratory conditions. It also damages many plants by interfering with photosynthesis and growth.

The other ideas mix up where ozone is and what it does. Stratospheric ozone sits high up and protects us from UV radiation; it’s not what causes ground-level smog. The claim that ground-level ozone warms the stratosphere isn’t accurate, and ozone doesn’t reduce visibility by absorbing rainfall. While smog can reduce visibility, the essential point about ground-level ozone is its health and plant effects and its role as a major smog component.