Question: Under what condition(s) does a UE (User Equipment) consider an MBS (Multicast-Broadcast Service) service as part of the MBS services of interest, in relation to receiving or being interested in receiving the service via a broadcast MRB (Media Resource Bundle)?
Option 1: If the UE is currently transmitting data and the service's session is paused.
Option 2: If the UE is receiving or wants to receive the service via a broadcast MRB, the service's session is ongoing or about to start, and specific MBS FSAIs (Frequency Selective Access Indicator Sets) for the service are included in SIB21 from the PCell.
Option 3: If the UE has previously received the service but the session has ended, and no frequency mapping is provided in SIB21 for that service.
Option 4: If the UE is in idle mode and the service's start time is indicated as immediate in the USD.
Explanation: This option correctly outlines the conditions under which a UE considers an MBS service to be of interest. These include: (1) the UE's intent to receive the service via broadcast MRB, (2) the service session being ongoing or imminent, and (3) the presence of specific MBS FSAIs for the service in SIB21 acquired from the Primary Cell (PCell), ensuring alignment with the specified conditions for determining services of interest.