Which two options accurately describe the implementation of Fibre Channel domain IDs?

Which two options accurately describe the implementation of Fibre Channel domain IDs? (Choose two.)
A. Are assigned on a peer-switch basis
B. Are assigned on a per-line card basis
C. Must be the dame on all on the Fibre Channel switch in the fabric
D. Must be unique on all the Fibre Channel switches in the fabric
E. Are assigned on a per-VSAN basis