You are creating an Ethernet channel that spans two or more switches. Which feature must be supported by
the switches?

A.
Cross stack

B.
None; Ethernet channel cannot span switches

C.
Fast port

D.
Spanning tree

Explanation:
Cross stack can span an EtherChannel across two switches. All of the links of the EtherChannel will be active
at any time. So if you configured an EtherChannel using four ports on a blade and connected two ports to each
of two switches configured for cross stack, your traffic would be flowing across all 4 ports.