Question: What triggers an MBS capable UE to start acquiring the MBSBroadcastConfiguration message on MCCH in a cell?
Option 1: Receipt of SIB19
Option 2: MCCH information change notification, or entering a cell providing SIB20, or receiving sCellSIB20
Option 3: Handover from another cell
Option 4: Periodic timer expiration
Explanation: According to the specifications, an MBS capable UE starts acquiring the MBSBroadcastConfiguration message on MCCH in a cell when it receives an MCCH information change notification, or enters a cell providing SIB20, or receives sCellSIB20. This ensures that the UE stays updated with the latest MBS broadcast configuration in the concerned cell.