Question: In a UTRAN TDD environment, what triggers the RNC to initiate the Enhanced Relocation Resource Release procedure towards the BSS, specifically releasing pre-allocated resources for a UE?
Option 1: Successful handover of the UE from UTRAN TDD to GERAN
Option 2: Periodic UE context update between RNC and BSS
Option 3: Receipt of a new UE connection request at the RNC
Option 4: Failure of the enhanced relocation process from UTRAN TDD to GERAN
Explanation: The Enhanced Relocation Resource Release procedure is initiated due to the failure of the enhanced relocation from UTRAN TDD to GERAN, triggering the release of pre-allocated UE resources.