Forgotten security questions
How do you recover your security questions?
Congratulations on being the next victim of Apple's current SNAFU!
If you don't have a rescue email address set, then you're SoL.
If you do, then reset your info and check in there.
If not, you'll have to contact iTS, and wait for God knows how long for Apple to complete its pending investigation in this SNAFU.
iTunes Store Support