The conclusion that can be drawn from the poem's structure is best described by the option: "The use of dashes rather than periods throughout shows that the poem is one long thought about hope."
Emily Dickinson frequently uses dashes to create a sense of fluidity and to convey continuous thought, which aligns with the theme of hope being an ongoing, enduring presence in one's life. The poem’s structure emphasizes the persistent nature of hope, suggesting that it is a continuous and integral part of the speaker’s experience.