The correct answers are: B) the dystopian world that Gregor enters as an insect, and C) Gregor's sudden transformation into a giant insect.
A Kafkaesque situation is a nightmarish one, and also strongly surreal, so in that sense, the options that relate the most to said expression are the ones that have to do with dream-like things, like the dystopian world and Gregor becoming an insect.
Fiction in which the author self-consciously <span>to the artificiality or literariness of a work by parodying or departing from novelistic conventions</span>