Question: Under what conditions does a UE (User Equipment) release the RLC (Radio Link Control) entity and logical channel for an additional sidelink RLC bearer in NR (New Radio) sidelink communication, specifically for unicast transmissions?
Option 1: Upon receiving any RRC (Radio Resource Control) Reconfiguration message, regardless of the trigger source.
Option 2: Only when the release is triggered by a change in the system information block (SIB) related to sidelink configurations.
Option 3: Exclusively if the UE's current sidelink configuration matches indices listed in `sl-RLC-BearerToReleaseList` within an RRCReconfiguration message, but not for dedicated NR configurations.
Option 4: If the additional sidelink RLC bearer release is triggered due to reception of `RRCReconfigurationSidelink` or by configuration within `sl-ConfigDedicatedNR`, `SIB12`, `SidelinkPreconfigNR`, or indication from upper layers, for indices part of the current UE sidelink configuration.
Explanation: This option correctly encompasses all specified conditions under which a UE releases the RLC entity and logical channel for an additional sidelink RLC bearer in unicast NR sidelink communication. These include triggers from `RRCReconfigurationSidelink` messages, dedicated configurations, system information blocks, preconfigured settings, and indications from upper layers, provided the bearer indices are part of the UE's current sidelink configuration.