In an Air Traffic Services unit applying Team Resource Management (TRM), what is the primary operational purpose of structured cross-checking between the Executive (Radar) Controller and the Planning/Coordinator Controller?

1. To provide redundant cognitive trapping and error detection before clearances are transmitted or flight plan conflicts develop
2. To allow one controller to sleep while the other manages the entire sector alone
3. To ensure that both controllers take their meal breaks simultaneously
4. To calculate individual controller commission fees per aircraft handled