For an 80m distance between wiring closets, using SFP+ transceivers is appropriate as they can support longer distances than standard copper interfaces. Ports 1/1/51 and 1/1/52 are typically reserved for uplinks on Aruba CX 6200F 48G switches and can support SFP+ transceivers, making them suitable for a redundant link-aggregation port configuration.

The correct way to configure the routable interface for the subnet to be associated with this VLAN is to create an SVI Switched Virtual Interface (SVI) Switched Virtual Interface (SVI) is a virtual interface on a switch that represents a VLAN and provides Layer 3 routing functions for that VLAN . SVIs are used to enable inter-VLAN routing , provide gateway addresses for hosts in VLANs , apply ACLs or QoS policies to VLANs , etc . SVIs have some advantages over physical routed interfaces such as saving interface ports , reducing cable costs , simplifying network design , etc . SVIs are usually numbered according to their VLAN IDs (e.g., vlan 10) and assigned IP addresses within the subnet of their VLANs . SVIs can be created and configured by using commands such as interface vlan , ip address , no shutdown , etc . SVIs can be verified by using commands such as show ip interface brief , show vlan , show ip route , etc . in the subnet on the 6300M stack. An SVI is a virtual interface on a switch that represents a VLAN and provides Layer 3 routing functions for that VLAN. Creating an SVI in the subnet on the 6300M stack allows the switch to act as a gateway for the users in that VLAN and enable inter-VLAN routing between different subnets. Creating an SVI in the subnet on the 6300M stack also simplifies network design and management by reducing the number of physical interfaces and cables required for routing.
The other options are not correct ways to configure the routable interface for the subnet to be associated with this VLAN because:
Create a physically routed interface in the subnet on the 6300M stack for each downstream switch: This option is incorrect because creating a physically routed interface in the subnet on the 6300M stack for each downstream switch would require using one physical port and cable per downstream switch, which would consume interface resources and increase cable costs. Creating a physically routed interface in the subnet on the 6300M stack for each downstream switch would also complicate network design and management by requiring separate routing configurations and policies for each interface.
Create an SVl in the subnet on each downstream switch: This option is incorrect because creating an SVI in the subnet on each downstream switch would not enable inter-VLAN routing between different subnets, as each downstream switch would act as a gateway for its own VLAN only. Creating an SVI in the subnet on each downstream switch would also create duplicate IP addresses in the same subnet, which would cause IP conflicts and routing errors.
Create an SVl in the subnet on the 6300M stack, and assign the management address of each downstream switch stack to a different IP address in the same subnet: This option is incorrect because creating an SVI in the subnet on the 6300M stack, and assigning the management address of each downstream switch stack to a different IP address in the same subnet would not enable inter-VLAN routing between different subnets, as each downstream switch would still act as a gateway for its own VLAN only. Creating an SVI in the subnet on the 6300M stack, and assigning the management address of each downstream switch stack to a different IP address in the same subnet would also create unnecessary IP addresses in the same subnet, which would waste IP space and complicate network management.

When generating a Multiple Pre-Shared Key (MPSK) for headless devices using the ClearPass self-service registration page, the MAC address of the device is required. MPSK associates a unique PSK with the MAC address of a device, providing a way to authenticate devices that may not have a user interface.