A1\#show spanning-tree VLANOOO1 VLANEBO2 Spanning tree enabled protocol ieee Root ID Priority 32770 Address 54a2.74ebcose Cost 19 Port 3 (FastEthernet /3 ) Hello Time 2sec Max Age 20sec Forward Delay 15sec Bridge ID Priority 32770 (priority 32768 sys-id-ext 2) Address 689c.e230.3880 Hello Time 2sec Max Age 20sec Forward Delay 15sec Aging Time 300sec Interface Role Sts cost Prio.Nbr Type Fa/1 Altn BLK 19128.1P2P Fae/2 Altn BLK 19128.2 P2p Fae/3 Root FWD 19128.3P2p Fae/4AltnBLK19128.4P2p According to the output, which switch is the root switch? a. DI b. Al c. D2