In the scenario provided, SW1 is configured with 'switchport mode dynamic auto' which means it is willing to convert the link to a trunk link if the connecting switch is set to trunk or desirable mode. Since SW2 also appears to be set to 'switchport mode dynamic auto', neither switch is initiating the trunking negotiation. To resolve this issue: * Option C: Configuring 'switchport mode trunk' on SW2 would manually set the port into permanent trunking mode which would then negotiate with SW1 and form a trunk. * Option D: Configuring 'switchport nonegotiate' on SW1 would disable Dynamic Trunking Protocol (DTP) negotiation messages. This should be done if you are setting one side of the connection (SW2) to a static trunk because DTP messages are unnecessary in this case.