The correct answer is A.
At the beginning of the novel, when Gregor first discovers he has transformed into an insect, he thinks about his current working situation. We can see that Gregor works as a travelling salesman. He dislikes the job, but does it to pay off his parent's debts. He is the sole supporter of the family. This reflects the family structure of that time.
However, after Gregor's metamorphosis, he loses the possibility to work. Due to this his family has to get jobs of their own in order to support not only themselves but also Gregor.