Question: In a USIM's EFePDGSelection file, what does an ePDG Priority value of '0000' (as a 2-Byte integer) indicate for a specific PLMN?
Option 1: The highest preference order for selecting an ePDG in that PLMN.
Option 2: The lowest preference order for selecting an ePDG in that PLMN, but still allowing selection.
Option 3: An invalid or reserved value, as the actual priority range starts from '0001'.
Option 4: That the ePDG selection should always use Operator Identifier FQDN format for this PLMN.
Explanation: According to specifications, a 2-Byte integer ePDG Priority implies valid values start from '0001', indicating a preference order. '0000' doesn't specify a preference order or relate to FQDN format selection, suggesting it's an invalid, reserved, or unspecified value within priority settings.