Chemicals Used by Humans Have Reduced the Concentration of Ozone

Chemicals used by humans have reduced the concentration of ozone (O₃) in the stratosphere over both the North and South poles. Why is the reduction of ozone dangerous to humans?

A) Localized changes in the Earth's atmosphere can alter the general global circulation and rainfall patterns.
B) The ozone layer absorbs ultraviolet light, a known mutagen; if it is reduced, the UV exposure at ground level will significantly increase.
C) Ozone is critical for the recycling of oxygen from carbon dioxide.
D) With reduced ozone concentrations the fixation of nitrogen gas to nitrate (NO₃) will occur too slowly.