Question: In which scenario is the Forbidden TAI(s) Information Element (IE) included in a message?
Option 1: When the message is sent via terrestrial E-UTRAN access.
Option 2: When the message is sent via satellite E-UTRAN access.
Option 3: When the UE is in idle mode.
Option 4: When the UE is performing a tracking area update.
Explanation: The Forbidden TAI(s) IE is included only when the message is sent via satellite E-UTRAN access, as specified in the 3GPP TS 24.301 standard. This is to ensure that the UE stores the forbidden tracking areas for regional provision of service correctly when communicating via satellite.