Final answer:
The rising action in 'The Old Man and His Grandson' is characterized by the old man's increasing mistreatment and the grandson's actions leading to a change in the family dynamics.
Step-by-step explanation:
The part of the story 'The Old Man and His Grandson' by the Brothers Grimm that contains the rising action is when the old man's condition deteriorates and his family's treatment of him becomes more callous. They move him behind the stove, give him an earthenware bowl, and, after it breaks, a wooden bowl. The rising action intensifies with the grandson's innocent and prophetic action of collecting bits of wood, prompting reflection and a change in his parents' behavior towards the grandfather.