Which of the following statements is an example of irony in “The Cask of Amontillado”?

A) Montresor vows to take revenge on Fortunato for an unknown offense.
B)Fortunato is dressed in motley as he is lured into the catacombs.
C) The servants are not home despite Montresor’s strict orders not to leave.
D)The reader never learns the fate of Fortunato.