What theme do these two excerpts from Franz Kafka's The Metamorphosis have in common?

It was so quiet all around too, even though there must have been somebody in the flat. "What a quiet life it is the family lead," said Gregor to himself, and, gazing into the darkness, felt a great pride that he was able to provide a life like that in such a nice home for his sister and parents. But what now, if all this peace and wealth and comfort should come to a horrible and frightening end? That was something that Gregor did not want to think about too much, so he started to move about, crawling up and down the room.
...

He spent the whole night there. Some of the time he passed in a light sleep, although he frequently woke from it in alarm because of his hunger, and some of the time was spent in worries and vague hopes which, however, always led to the same conclusion: for the time being he must remain calm, he must show patience and the greatest consideration so that his family could bear the unpleasantness that he, in his present condition, was forced to impose on them.
A.
the metamorphosis of Gregor from human to insect
B.
the breakdown of family structure
C.
the disconnection between mind and body
D.
the sense of duty toward one's family
E.
the basic need for food in every living thing