I made a grave error in counting for the last question, meaning unless you made the same counting mistake as I did, none of the answers would be correct. Depending on what you count as an individual set, the actual answer can be anywhere from 19 to 22 (24 if you're also willing to add in the two foreign Piraka Kaita sets) so I apologize for not double-checking my numbers before publishing the quiz. Unfortunately, it appears once a quiz has been published it cannot be edited, at least not by me.