Which two conditions can prevent FCoE from functioning properly across a link? (Choose two.)

Which two conditions can prevent FCoE from functioning properly across a link? (Choose two.)
A . LLDP is disabled.
B . PFC was negotiated across the link.
C . DCBX is enabled on the device.
D . The VFC interface is down.
E . The VSAN trunking protocol was enabled.

Answer: A, D