What function is served by this sentence in the paragraph?

Which statement best explains how the setting affects the meaning of the story? a. the water and wave motif conveys the queasy feeling the narrator has when walking alone at night. b. the firefly light conveys a feeling of nostalgia for long summer evenings spent with family. c. the phrase whispering and murmurs" suggests that the main character has fits of madness. d. the comparison of the street to a graveyard suggests that something is terribly wrong with society.