Question: In a 3GPP Northbound API framework, what is a prerequisite for CAPIF to authorize an API invoker to access a service API?
Option 1: Successful completion of the API invocation process
Option 2: Prior authentication of the API invoker by the network operator
Option 3: Availability of the requested service in the user’s subscription package
Option 4: Receipt of authorization information from the resource owner before API invocation
Explanation: This is correct because, according to the principles outlined for Northbound APIs in telecom standards like those from 3GPP, authorization typically precedes access to protected resources. The receipt of authorization information from the resource owner (the entity controlling access to the resource) before the API invocation is a standard flow in OAuth and similar authorization frameworks, ensuring that only approved invokers can access specific services or data, thus maintaining security and privacy.