Read this excerpt from The Call of the Wild by Jack London.

No lazy, sun-kissed life was this, with nothing to do but loaf and be bored. Here was neither peace, nor rest, nor a moment's safety. All was confusion and action, and every moment life and limb were in peril. There was imperative need to be constantly alert; for these dogs and men were not town dogs and men. They were savages, all of them, who knew no law but the law of club and fang.

Which type of conflict is shown in this excerpt?

character vs. self
character vs. nature
character vs. character
character vs. society