Question: Upon receiving an `RRCReconfiguration` message with a new `sl-MeasConfig` for Sidelink measurements, what action does a User Equipment (UE) take if the `sl-MeasConfig` includes a `sl-ReportConfigToAddModList`?
Option 1: Perform the sidelink measurement object removal procedure.
Option 2: Perform the sidelink reporting configuration addition/modification procedure.
Option 3: Initiate a new RRC connection setup to confirm the changes.
Option 4: Ignore the `sl-ReportConfigToAddModList` and continue with existing configurations.
Explanation: When a UE receives an updated `sl-MeasConfig` with a `sl-ReportConfigToAddModList` within an `RRCReconfiguration` message, it is instructed to update its reporting configuration for sidelink measurements. This involves adding new or modifying existing reporting configurations as specified in the list. Thus, the correct action is to perform the sidelink reporting configuration addition/modification procedure, ensuring the UE aligns with the network's updated measurement reporting requirements for sidelink communications.