In which of these excerpts from the story does Gregor seem to maintain some even slight thoughtfulness for his family

D.

Explanation:

Once during that long evening, the door on one side of the room was opened very slightly and hurriedly closed again; later on the door on the other side did the same; it seemed that someone needed to enter the room but thought better of it. Gregor went and waited immediately by the door, resolved either to bring the timorous visitor into the room in some way or at least to find out who it was; but the door was opened no more that night and Gregor waited in vain.