A cold wind raked across the barren moor and night was beginning to set in when we reached our final destination. The horses' hooves beat a steady drum as the carriage proceeded up the sweeping length of the driveway. At last we came to a stop in front of a crumbling mansion. One light shone brightly near an upper window, but the rest of the house was in inky darkness.

Which of these images from the selection most clearly contributes to the mood? The mood is bleak and eerie.

a. the light shining in the upper window
b. the sweeping length of the driveway
c. the steady drum of the horses' hooves
d. the cold wind raking across the moor