Answer:
d. The narrator has plotted his revenge in secret.
Step-by-step explanation:
Edgar Allen Poe's Dark Romantic short story "The Cask of Amontillado" tells the story of murder and revenge by the character Montresor. This story is a tale of a secret revenge murder.
In the story, the character of Montresor felt that he had been insulted by his friend Fortunato. So, he secretly planned a revenge for him. He invited Fortunato, a wine connoisseur to taste a special type of wine, the Amontillado. For the tasting, he had lured a very drunk Fortunato into his family catacombs. There, he chained him to a rock and built a wall at the entrance, thus blocking passage completely. The passage given is referring to the speaker's plotting of the revenge in secret which Fortunat have no idea about.