Which Example Best Demonstrates Habituation

Which example best demonstrates habituation?

A) Having been recently stung by a bee, Sara is now highly anxious whenever she is outside and hears a buzzing sound.
B) After being on campus for two weeks, Mario sleeps through the night instead of being awakened by the daily 2 a.m. train.
C) Due to hearing loss from a firecracker incident, Justin does not hear the humming of the transformer outside his room.
D) Having just returned home from a two-hour rock concert, Amber turns up the volume on her television so high that her next-door neighbors complain.