Read this excerpt from The Call of the Wild.
For two days and nights Buck never left camp, never let Thornton out of his sight. He followed him about at his work, watched him while he ate, saw him into his blankets at night and out of them in the morning. But after two days the call in the forest began to sound more imperiously than ever. Buck's restlessness came back on him, and he was haunted by recollections of the wild brother, and of the smiling land beyond the divide and the run side by side through the wide forest stretches. Once again he took to wandering in the woods, but the wild brother came no more; and though he listened through long vigils, the mournful howl was never raised.
How has Buck changed?
He has become more anxious about the call from the wild.
He has become less haunted by his dreams.
He has become more loyal to all mankind.
He has become less aware of his past life as an obedient pet.
He has become less aware of his past life as an obedient pet.
To determine how Buck has changed, we can analyze the given excerpt from "The Call of the Wild." The passage states that Buck never leaves camp and constantly watches over Thornton for two days. He follows Thornton's every move, ensuring his safety. However, the call of the wild starts to sound more compelling to Buck, and he becomes restless. He starts reminiscing about his wild brother and the vast forest beyond the divide. Eventually, Buck's restlessness compels him to wander in the woods. However, it is important to note that his wild brother does not appear, and Buck never hears the mournful howl he longs for.
Based on this information, we can conclude that Buck has become more anxious about the call from the wild. Despite his loyalty to Thornton, the urge to pursue his instincts and explore the untamed wilderness becomes stronger. Therefore, the correct answer is: He has become more anxious about the call from the wild.