Answer:
B. Chlorofluorocarbon emissions
Explanation:
During the 1970s, '80s, and '90s, humans were emitting large quantities of chlorofluorocarbons (CFCs), which led to the depletion of the ozone layer and the creation of ozone holes at the Earth’s poles. These substances were used in various products, such as refrigerants and aerosol sprays, and they contributed significantly to the increase in the size of the ozone hole during that period.
