The MAC address table of SW1 is shown in the figure.

The MAC address table in the exhibit contains learned entries for 0050-5600-0001 on GE1/0/1 and 0050-5600-0002 on GE1/0/2, but there is no entry for destination MAC 0050-5600-0003. A frame arriving from PC1 on GE1/0/1 with an unknown unicast destination is therefore flooded within the VLAN. Huawei Ethernet switching behavior sends the unknown unicast frame through all other eligible Layer 2 interfaces in that VLAN, while never sending it back through the ingress interface. In the shown topology, the remaining interfaces are GE1/0/2, GE1/0/3, and GE1/0/4. Consequently, the frame is sent through options A, D, and B respectively. GE1/0/1, option C, is excluded because it is the ingress interface from which SW1 received the frame. If SW1 later learns 0050-5600-0003 on a specific port, subsequent unicast frames can be forwarded only through that learned port. For the empty destination entry shown, the verified answer is A, B, and D.