Final answer:
The motivation of the character in 'To Build a Fire' is survival, as he is focused on rebuilding a fire to prevent frostbite in the harsh Yukon wilderness.
Step-by-step explanation:
In the excerpt from To Build a Fire, the character's motivation is survival. He is in a desperate situation, having to rebuild a fire in the freezing Yukon after his previous fire has been extinguished. The text illustrates his contemplation of the advice from an old-timer, highlighting his regret at not having a companion who could assist in such a critical moment. His recognition of the severity of his situation and the focus on needing to successfully build the fire to avoid frostbite and possible amputation of his toes underscores that his primary concern is survival against the harsh elements of the wilderness.