Question: What is the format of the realm part in a SUPI containing a GCI, if the operator owns a PLMN ID?
Option 1: The realm part should be in the form "mnc<MNC>.mcc<MCC>"
Option 2: The realm part should be in the form "5gc.mnc<MNC>.mcc<MCC>.3gpp"
Option 3: The realm part should be in the form "operator.com"
Option 4: The realm part should be in the form "5gc.mnc<MNC>.mcc<MCC>.3gppnetwork.org"
Explanation: According to the 3GPP TS 23.003 specification, if the operator owns a PLMN ID, the realm part of the NAI for SUPI should be in the form "5gc.mnc<MNC>.mcc<MCC>.3gppnetwork.org". This format is used to identify the operator owning the subscription.