Answer: B. hubris
Step-by-step explanation:
The key word in Ismene's lines is foolishness. Since Antigone and some other characters acted this way, the closest meaning would be hubris since the definition of hubris is excessive pride or self confidence. This element was the main cause of the tragedy in Antigone.
Anagnorisis is wrong because it is when a character makes a critical discovery.
Peripeteia is wrong because it means the sudden reversal/change in circumstances, which did not happen in Antigone.
Catastrophe is also wrong because it would be an event that caused disaster, which wasn't really the main point of the play.