Question: Upon receiving an `MBMSCountingRequest` message, what action does a UE in RRC_CONNECTED mode take if it is interested in receiving at least one service via an MRB (Multicast Radio Bearer) listed in the `countingRequestList`, and multiple entries are included in the `mbsfn-AreaInfoList`?
Option 1: Include the `mbsfn-AreaIndex` in the `MBMSCountingResponse` message, set to the index of the entry corresponding with the MBSFN (Multicast/Broadcast Single Frequency Network) area used for the received `MBMSCountingRequest`, and submit the response.
Option 2: Ignore the `mbsfn-AreaInfoList` and directly submit an `MBMSCountingResponse` with a generic index for all interested services.
Option 3: Delay submission of the `MBMSCountingResponse` until all modification periods have been evaluated to avoid duplicate responses.
Option 4: Respond only if the UE is currently receiving (not just interested in) the MBMS service via an MRB, disregarding unicast bearer services.
Explanation: According to the specifications for handling `MBMSCountingRequest` messages, if a UE in RRC_CONNECTED mode is interested in receiving at least one service via an MRB and multiple MBSFN area entries are provided, it must include the specific `mbsfn-AreaIndex` corresponding to the MBSFN area used for the received request in its response. This ensures accurate counting per MBSFN area for services of interest.