问题：

[单选] Which statement about SAN port channels configured on Cisco Nexus 5000 Series Switches is true？（）  

A .  A single SAN port channel can have both Fibre Channel and virtual Fibre Channel interfaces. 
B .  SAN port channels can include up to 16 interfaces.
C .  SAN port channels distribute traffic across all links in the port channel when source ID and destination ID load balancing are used.
D .  The links in SAN port channels can be connected to different sets of switches.
E .  The On mode of operation means ports only operate as part of a SAN port channel or remain inactive.