Answer:
The correct answer is: "The way a train moves along mountains and through cities".
Step-by-step explanation:
Emily Dickinson wrote this poem and published around 1891. The poem depicts an "iron horse", which is a railroad engine called that way by North American Indians in reference to the first train they had ever seen. Therefore, the poem describes "the way a train moves along mountains and through cities". Along the whole stanzas, it is possible to identify Nature elements concerned with wild life and horses, compared to city lifestyle and the role a train has played around them. The speaker uses natural elements to whether refer to wild life, with valleys, mountains, hills, or to refer to roads, tanks, a stable door, and more. By comparison, a horse living background is changed by lines and stanzas with an "iron horse".