How do ground-level ozone and stratospheric ozone differ in health effects and location?

How do ground-level ozone and stratospheric ozone differ in health effects and location?

• A. Ground-level ozone shields against UV radiation; stratospheric ozone causes respiratory problems.
• B. Both are equally harmful pollutants at ground level.
• C. Ground-level ozone is a pollutant that causes respiratory problems; stratospheric ozone protects life by blocking UV radiation.
• D. Ground-level ozone is beneficial to health; stratospheric ozone is harmful to lungs.

Answer: (C)