Answer:
The description in the excerpt helps readers understand the following about Thornton:
D. He has a playful and affectionate nature.
Step-by-step explanation:
"The Call of the Wild" is a novel by Jack London. The story is about a Buck, a dog that, being stolen from his family and his comfortable life, has to rapidly learn and adapt to his new and harsh life as a sled dog.
John Thornton is one of the men who become Buck's owner. However, unlike others who were willing to even beat Buck to death, Thornton has a playful and affectionate nature, as is revealed in the excerpt. Instead of regarding Buck as a "machine," just something to pull the sled from one place to another, Thornton truly sees Buck as the loving animal he is. He is kind to him. The excerpt describes one of these affectionate moments in which Thornton pets Buck and speaks to him lovingly, yet playfully.