The best statement that analyzes how Hugo uses irony in this example is:
Hugo uses dramatic irony by creating a situation where the audience knows something that the main character does not.
This statement captures the essence of the irony in Quasimodo's attempt to protect Esmeralda from the gypsies, wherein the audience is aware that the gypsies are actually coming to her rescue, creating a contrast between Quasimodo's perception and the reality understood by the audience.