Hi. I've reinstalled a copy of Mountain Lion and now I cannot sign into the App Store or iTunes. I've entered my correct Apple ID and password but I'm getting a message in red text stating that "An Apple ID verification code is required to sign in. Type your password followed by the verification code shown on your other devices". The trouble is that I don't have, in fact I have never had, another Apple device, so how can I access the verification code? When I sign into my Apple account via a web browser I can choose to have the verification code sent to my phone via text message, but there is no such option when attempting to sign into the App Store or iTunes. I'd appreciate some help with this. I must be overlooking something very simple. I find it hard to believe that I'm effectively locked out of my Mac because I don't have another Apple device. Thank you.