The correct answer is option D ("It reveals how weary the speaker is of waiting to see what effect she might have had on others").
Throughout this poem, the author expresses her hope of getting to see the youth evolve by the hand of the elder's teaching; while at the same time being anxious for the future and worried of what will be of her well-being. She's starting to feel tired and afraid that she might not get to experience one of the few joyous things she can envision about aging.
She talks about needing a staff to get by as she gets older, as this is a long stick used to support a person's walking.
Hope this helps!