The answer to yout question is letter D.It sets up the climax of the story, in which Samara presents her plan to the zoning board.
Since this paragraph explains the reason why she´s at the library, and that´s just because Samara is planning on how to present her ideas to the board, which immediatly leds on the next paragraph on more details about the presentation and how the presentation goes which is the main part of the story is the <u><em>Climax </em></u>of the story.