What is the critical safety procedure during a position relief (shift handover) between air traffic controllers?

1. A structured, verbal briefing covering current traffic picture, pending clearances, active weather/NOTAMs, runway in use, and equipment status, followed by a shared monitoring period where both controllers observe the display together before the outgoing controller steps away.
2. The outgoing controller walks away immediately without speaking to the incoming controller.
3. The incoming controller starts issuing clearances before looking at the radar display.
4. The position is left unmanned for 10 minutes between shifts.