Which statement about NPIV is true？（）
- A NPIV provides a means to assign multiple Fibre Channel IDs to a single N-port.
- B NPIV can be enabled on a per-VSAN basis.
- C NPIV requires a "write erase" and then reload the switch in order to come up into NPIV mode.
- D NPIV is a Cisco proprietary feature and as such works only between two Cisco switches.
- E NPIV must not be enabled on a switch that is also running N-port virtualization.