Haven't read that story, but going from the title I am going to say A.
Buck is a better lead dog because he displayed good judgment, intelligence, the ability to keep order, and the skill to make the team work as hard as possible. Spitz was a great dog and leader; Buck was superior even to him.
Buck's leadership skills are very strong. He has a knack for making the other dogs do their share of the work, and he is also a good teacher for the new dogs added to the team.
