Question: When deriving a home network domain name from an IMSI for WLAN access, what action is taken if the Mobile Network Code (MNC) is determined to be 2 digits long?
Option 1: The MNC is appended directly to the MCC in the domain name without modification.
Option 2: A zero is added at the beginning of the 2-digit MNC before creating the "mnc<MNC>.mcc<MCC>.3gppnetwork.org" part of the domain name.
Option 3: The IMSI's Mobile Subscriber Identification Number (MSIN) is used to determine the correct format for a 2-digit MNC.
Option 4: The WLAN UE defaults to using a 3-digit MNC format and appends an additional digit to the MNC.
Explanation: According to the specified process, if the MNC is identified as being 2 digits long, a zero must be added at the beginning of the MNC. This ensures consistency in the formatting of the domain name, facilitating accurate identification and authentication within WLAN access.