Loop protection is a feature that detects and prevents loops in layer 2 networks. Loop protection can be enabled on ports, LAGs, or VLANs. When loop protection is enabled, the switch sends periodic loop protection messages on the interface and expects to receive them back. If a loop protection message is received back on the same interface, it indicates a loop and the switch takes an action to disable the interface or block trafficon it3. The loop-protect re-enable-timer command is used to configure the length of time the switch waits before re-enabling an interface that was disabled due to loop detection. The default value is 0, which means that the interface remains disabled until manually re-enabled3. To automate the process of resuming the port operational state once a loop on a client port is cleared, the loop-protect re-enable-timer command can be used with a non-zero value on the interface range that includes the client ports3. Therefore, answer C is correct.

References: 1: Aruba Campus Access documents and learning resources 3: Configuring loop protection - Aruba