Which sentence from the story best indicates the unreliability of the narrator?
a) " i was never kinder to the old man then during the whole week before i killed him "
b) " to think that there i was, opening the door, little by little, and he not even to dream of my secret deeds or thoughts."
c) " no doubt i now grew very pale; - but i talk to more fluently, and with a heightened voice."
d) " i swung the chair upon which i had been sitting, and grated it upon the boateds, but the noise arose over all and continually increased."