Question: What is the primary reason for using the `INSUFFICIENT_BEARER_RESOURCES` (2) Abort-Cause AVP value in a RAR indicating a bearer release, specifically in GPRS contexts?
Option 1: Overload of the Policy and Charging Rules Function (PCRF) server
Option 2: Successful deactivation of a PDP Context due to normal signaling handling
Option 3: Insufficient resources at the transport gateway (e.g., GGSN for GPRS)
Option 4: Initiation of PS to CS handover by the PCRF
Explanation: The `INSUFFICIENT_BEARER_RESOURCES` (2) Abort-Cause AVP value is specifically used when the bearer has been deactivated due to insufficient resources at a transport gateway. In GPRS contexts, this would typically refer to a lack of necessary resources at the Gateway GPRS Support Node (GGSN), highlighting a critical infrastructure limitation impacting bearer establishment or maintenance.