Final answer:
Buck is characterized by his resilience and ability to endure the harsh conditions of the Klondike, setting him apart from other sled dogs.
Step-by-step explanation:
The statement that best describes how Buck differs from the other dogs in The Call of the Wild is that Buck is better at handling the strain of traveling long distances. This is evident from the fact that Buck's innate animal nature allows him to survive the harsh conditions and brutal behavior he encounters in the Klondike after being sold into sled dog service. The excerpt from The Call of the Wild paints Buck as a character that is both enduring and resilient, traits that presumably set him apart from the rest of the sled dogs.