Question: What is a key characteristic of a HA-APN Network Identifier, in addition to following the standard APN format, when used to access a service associated with a Home Agent (HA)?
Option 1: It must contain 'ha-apn.' or 'w-apn.' to indicate HA association.
Option 2: It shall not contain 'ha-apn.' or 'w-apn.' and not end in '.3gppnetwork.org'
Option 3: It is limited to a single label for simplicity in DNS coding.
Option 4: It always starts with a Reserved Service Label without exception.
Explanation: This option correctly highlights a crucial distinction for HA-APN Network Identifiers. The absence of 'ha-apn.' or 'w-apn.' and not ending in '.3gppnetwork.org' is essential for its proper interpretation, especially when accessing services associated with a Home Agent (HA), ensuring seamless operation within telecom networks.