Read the excerpt from The Call of the Wild.

All the stiffness and gloss had gone out of his beautiful furry coat. The hair hung down, limp and draggled... His muscles had wasted away to knotty strings, and the flesh pads had disappeared, so that each rib and every bone in his frame were outlined cleanly through the loose hide. . . .

The descriptive language in this scene best shows readers that Buck is

angry and resentful.
nervous and tired.
weak and gaunt.
gloomy and hopeless.