In Buck's transformation, what does he ultimately reject?

Buck's transformation throughout "The Call of the Wild" illustrates his journey from a domesticated pet to a primal creature, deeply connected to nature and his ancestral instincts. Ultimately, he rejects the bonds of civilization, which symbolize the constraints and comforts of human society that he once knew. This rejection signifies his embrace of a more authentic and instinctual existence.

As Buck faces the harsh realities of survival in the wild, he learns to trust his instincts and adapt to the environment, shedding the expectations and limitations imposed by civilization. His increased independence and the development of his natural instincts lead him to forsake the life of comfort and security that he once had as a household pet, exemplifying his transformation into a creature of the wild.

The other options refer to aspects of Buck's journey but do not encapsulate the core of his transformation as accurately as the rejection of civilization. For instance, while he indeed responds to the call of the wild, rejecting the companionship of other dogs, or pursuing food, these elements are part of his journey, not the primary shift in his identity. The culmination of Buck’s transformation is most clearly defined by his final abandonment of the trappings of civilized life, positioning him firmly as part of the wild.