When you do all your processing for either retraining or your initial physical in BMT youll find out for sure. Either way, its not a massive difference. If youre really bothered between the two and you have access to a Flight Medicine clinic, head down there to ask. However I can say as both someone who enlisted as TACP before I washed out and now a 4N0 that has done the physicals, it was the Ground Based Controller. Full disclosure, its been a couple years since Ive done one so it may have changed.