Read the following excerpt from "the cask of amontillado" and answer question.

the thousand injuries of fortunato i had borne as i best could, but when he ventured upon insult i vowed revenge. you, who so well know the nature of my soul, will not suppose, however, that gave utterance to a threat. at length i would be avenged; this was a point definitely, settled --but the very definitiveness with which it was resolved precluded the idea of risk. i must not only punish, but punish with impunity. a wrong is unredressed when retribution overtakes its redresser. it is equally unredressed when the avenger fails to make himself felt as such to him who has done the wrong.

it must be understood that neither by word nor deed had i given fortunato cause to doubt my good will. i continued, as was my in to smile in his face, and he did not perceive that my smile now was at the thought of his immolation.

based on the context clues, the word immolation most likely means
a. destruction
b. victory
c. failure
d. suffering