Transferring would be the correct answer.
I would say the correct answer is B. primitive man.
The point of the entire novel is that Buck is fighting his urges to go to the wilderness and succumb to his wild identity of a wolf. Thus, dreaming about the primitive man clearly portrays his struggle between his two identities, that of a domesticated dog and that of a wild wolf.
I would say either D or B but it depends on whether the Romantic ideals are personal to the character or if they’re a theme throughout the story :)
The answer is D. 9/11 Trade Center Attacks