Given the following output：  san-port-channel 12 is up   Hardware is Fibre Channel  Port WWN is 24：0c：00：0d：ec：d3：5c：00   Admin port mode is NP， trunk mode is on   Port mode is NP Port vsan is 1  Speed is 8 Gbps   Member[1] ： fc2/3  Member[2] ： fc2/4  What does "Speed is 8 Gbps" indicate？（）

• A、 The speed of the slowest interface in the port channel
• B、 The combined speed of all interfaces configured in the port channel
• C、 The combined speed of all interfaces in the port channel that are up
• D、 The speed that can be achieved if all buffers are used