In a rhetorical situation, what is the exigence? O the message of the text—what the writer is saying about the issue at hand
O the original reason for or cause of the writing—the issue that prompted the writer to say something
O the purpose the writer has for writing—what the writer ultimately hopes to accomplish
O the context for writing the historical events and cultural movements surrounding the text's creation

Explanation:

Exigence an event or circumstance that engenders rhetoric; the requirement is the one that starts the "loop" of the debate on rhetoric about a specific subject. Purpose: the desired results of (implicitly or explicitly) rhetorical speech defined by the rhetoric.

direct object would be the answer

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.