Question: In a ProSe Application ID, how is a Mobile Network Code (MNC) with only 2 significant digits represented in the PLMN ID to ensure inter-PLMN operability?
Option 1: By removing the least significant digit to fit the 3-digit format.
Option 2: By appending a "0" at the right side of the MNC to form the <MNC> label.
Option 3: By using only the 2 significant digits without any modification in the "mnc<MNC>" label.
Option 4: By inserting a "0" digit at the left side of the MNC to form the <MNC> in the "mnc<MNC>" label.
Explanation: To guarantee inter-PLMN operability, the MNC must be represented by 3 digits. When an MNC has only 2 significant digits, inserting a "0" at the left side ensures it meets the required format without altering its original value, thus maintaining compatibility and uniqueness in identifying the PLMN within the ProSe Application ID.