Read the excerpt from poe’s "the fall of the house of usher."

shaking this off with a gasp and a struggle, i uplifted myself upon the pillows, and, peering earnestly within the intense darkness of the chamber, hearkened -- i know not why, except that an instinctive spirit prompted me -- to certain low and indefinite sounds which came, through the pauses of the storm, at long intervals, i knew not whence. overpowered by an intense sentiment of horror, unaccountable yet unendurable, i threw on my clothes with haste.

which word from this excerpt could be used to argue that the narrator is unreliable?
a. “shaking” suggests the narrator’s nervousness.
b. “struggle” suggests the narrator’s weakness.
c. “indefinite” suggests the narrator’s lack of knowledge.
d. “overpowered” suggests the narrator’s lack of control.