Question: What happens to the PDN connection for USS communication if the UUAA-SM procedure fails during re-authentication or re-authorization?
Option 1: The PDN connection remains active and continues to be used for USS communication.
Option 2: The network initiates a new UUAA-SM procedure to try again.
Option 3: The associated PDN connection for USS communication is released.
Option 4: The UE supporting UAS services is disconnected from the network.
Explanation: According to the text, if UUAA-SM fails during re-authentication or re-authorization, or if the revocation of UUAA is initiated by the network, then the associated PDN connection for USS communication is released. This ensures that unauthorized access to USS communication is prevented and security is maintained in the network.