12.  In lines 470-475, what sensory details can be inferred and how are these related to the walls?

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.

no. but, i heard its a good book. you could look up the answers or summary on some website.