Refer to the exhibit.
Switches A and C are running PVST+ STP, and switch B is running 802.1Q STP, if the BPDU of the root in VLAN 1 is better than the BPDU of the root in VLAN 2, then there is no blocking port in the VLAN 2 topology. The BPDU of VLAN 2 never makes a full circle around the topology, it is replaced by the VLAN 1 BPDU on the B_C link, because B runs only one STP merged with VLAN ! STP of PVST+ Thus, there is a forwarding loop What does PVST+ do to correct this?
A.
Switch A sends PVST+BPDUs of VLAN 2 (to the SSTP address that is flooded by switch B) towards Switch C. Switch C will put port C-B into a type-inconsistent, which prevents the loop
B.
Switch B sends PVST+BPDUs of VLAN 1 (to the SSTP address that is flooded by switch A) towards Switch C. Switch C will put port C-B into a type-inconsistent, which prevents the loop
C.
Switch C sends PVST+BPDUs of VLAN 2 (to the SSTP address that is flooded by switch B) towards Switch C. Switch C will put port C-B into a type-inconsistent, which prevents the loop
D.
Switch A sends PVST+BPDUs of VLAN 1 (to the SSTP address that is flooded by switch B) towards Switch B. Switch A will put port C-B into a type-inconsistent, which prevents the loop