Question

chlorofluorocarbons are complex, abundant, and ______.
anthropogenic
naturally-formed
essential
unsteady

Explanation:

Chlorofluorocarbons (CFCs) are man - made (anthropogenic) compounds. They are not naturally - formed as they are synthetically produced. They are not essential (in fact, they are harmful to the ozone layer) and the term “unsteady” is not an appropriate description for their nature in this context. So the correct option is “anthropogenic”.

Answer:

A. anthropogenic