The figure below shows the partial topology of a campus network and the corresponding data...

The topology contains three Layer 3 interconnection VLANs: VLAN 12 between Core1 and ACC1, VLAN 13 between Core1 and ACC2, and VLAN 23 between ACC1 and ACC2. OSPF is enabled across the campus, while STP still controls Layer 2 forwarding on the VLAN links. If ACC2 GE1/0/3 is an alternate port, STP blocks service forwarding on the ACC1-ACC2 path. As a result, OSPF Hello packets cannot be exchanged across that blocked Layer 2 path and ACC1 and ACC2 cannot establish an OSPF neighbor relationship on VLAN 23, so C is true. Core1 still has routes for all three interconnection networks: VLAN 12 and VLAN 13 are directly connected, and information for VLAN 23 can be learned through OSPF from the access devices, making B true. Statement A is incorrect because ACC1 already has VLANIF 23 as a directly connected network rather than needing to learn that same connected segment through OSPF. Statement D is also false: STP can still be relevant on Layer 2 VLAN links even in a campus using Layer 3 routing.