A: The white hills appear in the first paragraph are the most significance of setting to the theme with no doubt that we can notice from the title of this story. And the station "between two lines of rails", seems the implication of two people standing face to face according to the story, while the surroundings of the station is a quite significance setting of the story.
The surroundings of the station is the symbol of this story as there are two sides of the station. The green side is obviously, represents life, the baby and a new beginning. This is the side where Jig stands to look at them, observing that they look like white elephants. Jig wants a life beyond the empty relationship she has shared with the American. The arid side which is barren represents death and dissipation, the kind of life she wants to give us. Jig does not want to give us the baby, she is identified with the life-filled side of the station. She appreciates the beauty of the hills, but the American does not. Also, the station is a place of transition, not a destination in itself, if they are heading there together or separately, is unsure in the story, and thus the setting emphases the decision that has to be taken and how there is still be a journey yet to be made.