What is the climax in the story of The Aged Mother?

Climax: At last, they reach the summit. The weary and heartsick youth gently released his old mother. Before he live his mother, the old woman told his son about the mark of the pile of twigs that will guide him to the way home. At that point, the farmer realizes that whatever happens he should not left his mother alone. So he decided that both of them will go home and will die together