Question: What does an Access-Availability-Change-Reason AVP value of '0' indicate in a Policy and Charging Control (PCC) scenario?
Option 1: The access has become unusable due to a network congestion issue.
Option 2: A change in the user's subscription status affecting access availability.
Option 3: The PCEF has detected a security breach on the access link.
Option 4: The availability of an access is changed due to Access Stratum indication.
Explanation: An Access-Availability-Change-Reason AVP value of '0' indicates that the change in access availability is a result of the Access Stratum indication, highlighting its influence on access availability decisions made by the Policy and Charging Enforcement Function (PCEF).