Question: In the context of Inter-Proximity Services (ProSe) function signalling, what information must the HPLMN ProSe Function include in a Match Request to facilitate charging for a monitoring UE by the local PLMN's ProSe Function?
Option 1: Only the discovered ProSe Application Code(s) and MIC
Option 2: The discovered ProSe Application Code(s), MIC, UTC-based counter, and the UE identity (IMSI or MSISDN)
Option 3: PC5-tech indicating the PC5 radio technology used by the UE, and the flag 'Metadata Requested' if applicable
Option 4: Discovery Type set to 'MONITORING_REQUEST_FOR_OPEN_PROSE_DIRECT_DISCOVERY' alone
Explanation: To enable the ProSe Function in the local PLMN to perform charging for the monitoring UE, the HPLMN ProSe Function must provide identifiable information about the UE. This is achieved by including the UE's identity (either IMSI or MSISDN) in the Match Request, alongside the necessary context of the discovered ProSe Application Code(s), MIC, and UTC-based counter, ensuring both authentication and billing can be accurately managed.