Which of the following statements about the MSP ring is correct?

The number of nodes on the MSP ring cannot exceed 16. .

Create a protection sub and select only the SDH network element. Do not select REG or WDM network elements.

When multiple protection subnets occupy the same port on the same board, "resource sharing" must be reached.

is assigned by VC4 means that different VCs4 are assigned to different protection subnets to implement MsPs only in certain channels