The bus driver was surprised when her first passenger asked her to turn the music down, because she thought the volume was fine. When the passenger said something, though, the driver realized the sound was too loud. The bus driver’s initial indifference to the volume can best be understood because

a. the volume was below her absolute threshold.

b. the driver had a decreased ability to determine the music’s pitch.

c. the just noticeable difference of the music was too great.

d. the driver had adapted to the volume of the music.

e. the driver was using bottom-up processing instead of topdown processing.