The correct answer to this question is C. A VLAN, or Virtual Lan, is a domain that is isolated and partitioned inside a computer network. They divide broadcast domains in the LAN system. In order to communicate between VLANs, traffic must be routed between them, which is known as "inter-VLAN routing."
In this case, a network administrator should configure 1, 2, 3, 4, 5, 6 (all six) links of the VLAN interfaces as routed ports in order to implement an inter-VLAN routing in the network. Routed ports work as a port on a router and are not associated with a particular VLAN.