What theme does the following excerpt from Franz Kafka’s The Metamorphosis deal with?

Hearing these words from his mother made Gregor realise that the lack of any direct human communication, along with the monotonous life led by the family during these two months, must have made him confused—he could think of no other way of explaining to himself why he had seriously wanted his room emptied out. Had he really wanted to transform his room into a cave, a warm room fitted out with the nice furniture he had inherited? That would have let him crawl around unimpeded in any direction, but it would also have let him quickly forget his past when he had still been human. He had come very close to forgetting, and it had only been the voice of his mother, unheard for so long, that had shaken him out of it. Nothing should be removed; everything had to stay; he could not do without the good influence the furniture had on his condition; and if the furniture made it difficult for him to crawl about mindlessly that was not a loss but a great advantage.

A the drudgery of middle-class life
B the breakdown of social structures
C the disconnection between mind and body
D the ineffectiveness of language