I breathed a song into the air, It fell to earth, I knew not where;
For who has sight so keen and strong,
That it can follow the flight of song?
1. Why can he not see where the song went?

He doesn't have a keen and strong sight.

Explanation:

Cheers!

in the section of speech is not

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.