In which two situations should you use out-of-band management?

When a network device fails to forward packets, in-band management through the network is typically inaccessible, necessitating out-of-band access via a console or auxiliary port for diagnosis and recovery.

ROMMON (ROM Monitor) access is a low-level diagnostic and recovery mode that can only be accessed through a direct console connection, which is a form of out-of-band management.

Management applications needing concurrent access to a device is typically a function of in-band management, allowing multiple users to connect over the operational network.

Requiring administrator access from multiple locations is a common use case for in-band management via network protocols like SSH or Telnet, not a specific reason for out-of-band management.

While a control plane failure often necessitates out-of-band management due to network disruption, the statement is a more specific internal diagnostic condition; however, in situations like this, the lack of packet forwarding (A) is the observable symptom that directly blocks in-band access, making A a more direct trigger for OOB.