Answer:
C. His foolishness.
Step-by-step explanation:
Edgar Allan Poe in "The Cask of Amontillado" portrays Fortunato in a humorous light who's drinking and enjoying the carnival wearing a clown's hat which symbolizes that he was being made fool by Montresor.
Fortunato dresses up as a jester with a colorful outfit full of patches filled with bright colors like purple, yellow or red along with the pom poms that add a feather to his silliness. His clown-like dress up with the cap and costume compliments his silly behavior as he behaves too like a clown. This all was a part of Montresor's plan to lure him and eventually murder him. Thus, Fortunato's carnival costume symbolizes his foolishness that Montresor takes advantage of.