Which of the Following Statements Is True About the Port

Which of the following statements is true about the port mirroring on Huawei devices?

A) Huawei devices support port mirroring on the control traffic sent to the CPU
B) Huawei devices support flow-based port mirroring. The mirrored traffic can be copied onto multiple observing ports
C) Traffic in the RSPAN is transmitted to observing ports in multicast mode
D) When the observing port becomes congested, mirrored packets cannot be discarded because these packets have higher priority than service traffic