D. He feels they represent awe-inspiring beauty.
In the first paragraph of Chapter I of Nature, Ralph Waldo Emerson expresses deep admiration for the stars. He writes that if the stars appeared only once every thousand years, people would marvel at their beauty and the wonder they inspire. Emerson uses this idea to emphasize how people take nature for granted because it is always available. His tone reflects reverence and awe, suggesting that the stars symbolize the mysterious and sublime beauty of nature.