What lesson does Buck learn when facing challenges in the wild?

Buck learns the importance of instinct and adapting as he confronts various challenges in the wild. Throughout his journey, he initially relies on the comforts of domestication but soon realizes that his survival hinges on his ability to tap into his primal instincts. As he faces dangers and learns from his experiences, he adapts his behavior and embraces the traits that are necessary for a life in the wild, such as hunting, fighting, and forming social bonds with other animals. This evolution signifies a crucial transformation in his character from a pampered pet to a creature in tune with his natural instincts, highlighting the theme of survival and the necessity of adaptation in the face of adversity.

The other choices do not encapsulate Buck's experience accurately. While intelligence plays a role in survival, it is his instinct that ultimately guides him. Trusting humans becomes less reliable as he witnesses their betrayal and cruelty. The idea of avoiding challenges entirely contradicts Buck's journey, as he learns that overcoming obstacles is vital for growth and survival. Thus, embracing instinct and the need to adapt is central to Buck's development throughout the narrative.