because forget security question
because i long time no use forget security answer.
MacBook Pro (13-inch, Mid 2012), Mac OS X (10.7.5)
Start here, and reset your security questions, you will receive an email to your rescue address, then go to manage your account > Password and Security and set your security questions.
If that doesn't help or you don't have a rescue address, you might try contacting Apple through iTunes Store Support