What significant value to VSANs contribute?

What significant value to VSANs contribute?

A.
VSANs are a logical segmentation of a physical switch into logical fabrics that allow customers to consolidate SAN islands.

B.
VSANs are physical segmentations in a logical switch fabric that allow customers to create separate SAN islands.

C.
VSANs are a logical segmentation of a physical fabric into Arbitrated loop topologies.

D.
VSANs are physical boundaries between blades on the MDS.