Answer:
Hopeful
Step-by-step explanation:
The tone of the given passage is hopeful. We can see that the Granddad is sad about changes that are going on, and his grandchild is trying to comfort him. They are not doing it in an energetic way but in more of a calm, compassionate way. They are not angry, nor do they share Granddad's sorrow. They are hopeful about their future together and are trying to make Granddad see that.