Refer to the exhibit.

The selected command is correct because the port is already restricted to one manually learned MAC address, and the requirement is to let the switch dynamically learn the connected endpoint while retaining port-security control. In Cisco Catalyst port security, a static secure MAC address is manually configured, while a sticky secure MAC address is dynamically learned and then added to the running configuration. This design is useful on access ports where the administrator wants the operational convenience of dynamic learning but still wants the switch to enforce the maximum secure-address limit. Once the endpoint MAC is learned, subsequent frames from different source MAC addresses can trigger the configured violation action, such as protect, restrict, or shutdown. The command must therefore enable sticky learning on the secured interface rather than simply changing the maximum, disabling port security, or configuring a normal switching feature. This is an access-layer security function, not a routing or QoS function. Reference topics: Catalyst port security, secure MAC addresses, sticky learning, access port hardening, Layer 2 campus design.