Answer: A. It reveals the author's feelings about his travel experience, by contrasting the ordered, uniform landscape of France and the wild, varied landscape of the American West.
In this excerpt, the author begins by telling us of his trip in France. In this case, the author is travelling by railway. However, we can see that he does not enjoy it as much as travelling on a stagecoach. He then reflects on the beauty of the American landscape as he saw it from his stagecoach. The author contrasts the two journeys and the two modes of transportation in order to inform us of his travel experience.