Question: In SRVCC operations towards UTRAN and GERAN, what is the default value set for the RAC in the Application-Unique String if it's not available from the Target ID?
Option 1: Hexadecimal value '00'
Option 2: Hexadecimal value 'FF'
Option 3: ASCII value 'NA'
Option 4: Decimal value '255'
Explanation: According to specifications, when the RAC is not available from the Target ID, the default value set for the RAC in the Application-Unique String is hexadecimal value 'FF', enabling the S-NAPTR procedure to initiate with a complete Application-Unique String based on the RAI FQDN.