The answer is B: chronological order, starting with Gregor´s transformation.
Kafka´s famous short story begins precisely when, one day, unexpectedly, Gregor Samsa wakes up to find himself transformed into a bug. From there the story progresses in chronological order, showing the perils of Gregor´s new form, his struggle to accommodate to his new life and his family´s reception, horror and disgust at his transformation.