Question: Which of the following logical functions provided by the SIP database is responsible for verifying a user's permission to access a visited network while roaming?
Option 1: Access Authorisation
Option 2: Service Authorisation Support
Option 3: Registrar Assignment Support
Option 4: User Security Information Generation
Explanation: Access Authorisation is the correct answer because it involves verifying that a user is allowed to roam to a visited network, which directly relates to controlling and managing access permissions for roaming users. This function ensures that only authorized users can access services while in a different network, enhancing security and compliance with operator policies.