Question: Under what conditions does a User Equipment (UE) release all Secondary Cells (SCells) that are part of its current configuration?
Option 1: When the UE receives an sCellToReleaseList or sCellToReleaseListSCG with a specific sCellIndex value.
Option 2: During RRC connection re-establishment, or when resuming from a suspended RRC connection/RRC_INACTIVE state.
Option 3: Upon handover to a different eNodeB (eNB) in the E-UTRAN network.
Option 4: When the UE's current configuration is updated with new SCell additions.
Explanation: A UE releases all configured SCells during RRC connection re-establishment, or when resuming from a suspended RRC connection/RRC_INACTIVE state. This ensures the UE's configuration is updated to reflect only currently valid SCells upon these transitions.