Which command enables NPIV on Cisco Nexus 5000 Series Switches and Cisco MDS switches?

Which command enables NPIV on Cisco Nexus 5000 Series Switches and Cisco MDS switches?
A. switch(config)# npiv enable
B. switch(config)# npivon
C. switch(config)# feature npiv
D. switch(config)# npiv proxy
E. switch(config)# np proxy-enable