i forgot my security question

if you mean the apple security questions the following article tells how you can reset these:

http://support.apple.com/kb/HT5312

if you still can't reset these at the appleid.apple.com site you will need to call applecare and let them verify your identity so they can reset the questions for you. 🙂

also for applecare to be able to reset the security questions they need to verify your identity and you at least MUST know the password to the apple ID you need to reset the questions for or they won't be able to help you.