Your network has two distribution layer switches, switcha and switchb, connected through trunk ports on each of their respective gi 0/1 interfaces. in addition, you recently connected an access layer switch to the network, switchc. switchc has several workstations and a server belonging to vlan 20. because the resources on vlan 20 are exclusive to the local workstations, you need to restrict vlan 20's traffic from passing though the network on the trunk ports of switchc.