I can't open the story to read and answer it :(
I believe the correct answer is B. <span>The narrator does not trust what Agnes tells her.
This is a gothic element because there's obviously a great mystery in the house, that is being hidden from the newcomer. Furthermore, her predecessor has died, and the reason is unclear. In Wharton's time and before, servants, maids, and other members of the lower social classes were to come to the rich mansions and do their duty without inquiring or showing any kind of inquisitiveness, even when the issue concerns them very much. Agnes, as a loyal servant, partakes in this secrecy, and won't admit to the speaker that something strange is happening.</span>
All a diary entry is is when you start a story by making it sound appealing to the reader. It makes the reader want to read on, and not stop until the end.