-Our actions affect not only us, but the environment around us.
-People should be more conscious of the
damage they do to their bodies.
Are these topics or themes?

Themes

Explanation:

A topic is normally presented in a more open-ended way while these are presented as statements, proving that they resemble morals more than topics.

Themes

Explanation:

Topics are different things to write about, and these are the messages (themes) that you learn or come from a story. I hope this helps!

i believe it is the first choice (1.)

because the major theme is(“both the wild and civilization have rules.”)

and also as u said,( based on what buck learns within the call of the wild, "both the wild and civilization have rules".this is true of humans within society as well.