How does the setting of the passage fit into the plot? (Endymion Springs)

A. The setting contrasts with the plot because the setting seems quiet, but there is
something puzzling going on in the library.
B. The setting contrasts with the plot because the setting seems spooky, but there is
nothing out of the ordinary going on in the library.
C. The setting helps move the plot to a conclusion because the setting is nighttime
and the library is about to close.
D. The setting helps move the plot to a conclusion because the setting is daytime
and people are still coming to the library.