Question: How does an MC (Mission Critical) service UE prioritize network selection for EPC-level roaming to ensure migration to partner MC systems is possible?
Option 1: By automatically selecting the PLMN with the strongest signal
Option 2: Through configuration of its User Preferred PLMN Selector list with a list of PLMNs that can migrate to one or more partner MC systems
Option 3: Using IMS-level roaming as the default for all mission-critical communications
Option 4: By querying the visited PLMN for its supported MC services before connection
Explanation: This is correct because, for EPC-level roaming, configuring the User Preferred PLMN Selector list with specific PLMNs that can migrate to partner MC systems allows the UE to prioritize network selection. This ensures seamless handover and continued access to mission-critical services when roaming between different Public Land Mobile Networks (PLMNs). This approach is tailored to the needs of mission-critical communications, which require reliable and uninterrupted service.