methods of filtering gasoline use of chlorofluorocarbons (CFCs) methods of radioactive waste storage use of mercury (Hg) compounds
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of these has been controlled in an attempt to reduce the depletion of ozone in Earth's atmosphere?
Possibilities:
- methods of filtering gasoline
- use of chlorofluorocarbons (CFCs)
- methods of radioactive waste storage
- use of mercury (Hg) compounds

use of chlorofluorocarbons (CFCs)