Sadly it can be debatable because the biological sex of the person will be decided by which sperm get ot the egg. So a second X or a Y. After that point, the brain of the fetus might develop in a direction different than what the chromozone wanted it to be for reasons I do not know. Because of that, multiple people will debate that the body was the right one and it's the mind that was incorrect.
Well seeing as people can be born with all sorts of outward deformities, it's fair to say the mind is the correct one.
@ Hanna; yeah, nothin' against you, I just think it's silly to debate whether or not people like that exist when it's been proven that yeah, they are born in the wrong body.
The only debatable issue is whether you choose to deny that fact or not. It's an odd subject for some (kind of understandably), but other than that I dunno what's so hard to grasp besides people choosing to be arrogant about it.