The thing which occupies most of Gregor's time as he spends months locked in his room is shown in the option : D. He thinks about his previous life and how unhappy and unfulfilled he was. The fate is cruel, from the routine which gradually made him sick, his life turned him into a helpless creature. Even though that his body is not like that of human being, his soul and memories are remain inside his shell, that means he always traces all back to then, asking himself : Why? Why didn't I engoy my life, why I chose this path? Is it a punishment for my mistakes?''. He compared his present and previous feelings and understood that the difference between them is almost none.
