If switch SWA is the master node of primary ring 1, and if switch SWD port GigabitEtherent2/0/1 fails, what can we learn from the above information?

The customer LAN switches SWA, SWB, SWC, and SWD form the RRPP ring main ring 1. Switch SWD is connected to switches SWB and SWC, but not to switch SWA.

The switch SWD has the following configuration information:

[SWD] rrpp domain 1

[SWD-rrpp-domain 1] ring 1 node-mode transit primary-port gigabitethernet 2/0/1 secondary-port

Gigabitethernet 2/0/2 level 0

If switch SWA is the master node of primary ring 1, and if switch SWD port GigabitEtherent2/0/1 fails, what can we learn from the above information?

A. SWA will send a Link-Down message to notify all nodes

B. The switch SWA immediately switches to the Failed state and releases the secondary port

C. The switch SWC immediately switches to the Failed state and releases the secondary port.

D. If the switch SWD finds that the port GigabitEthernet2/0/1 is Up again, it will immediately unblock the port.