This is a key event in The Call of the Wild. It was brought about by a conversation in the Eldorado Saloon, in which men waxed boastful of their favorite dogs. Buck, because of his record, was the target for these men, and Thornton was driven stoutly to defend him. At the end of half an hour one man stated that his dog could start a sled with five hundred pounds and walk off with it; a second bragged six hundred for his dog; and a third, seven hundred.

How does this event affect plot development?

It shows that Thornton believes in Buck.
It proves that Buck is stronger than other dogs.
It creates tension between Thornton and Buck.
It makes other men aware of Buck’s value.