How is storage multi-pathing configured between an ESX Server and a supported storage array?

A.
The multi-pathing driver is provided with ESX Server and is compatible with any supported storage array.

B.
Your storage array vendor must provide you a multi-pathing driver for ESX Server and an agent to be installed in each Guest OS.

C.
Your array vendor must provide you with an agent to be installed in each Guest OS.

D.
Your storage array vendor must provide you with a multi-pathing driver for ESX Server.

Explanation:
iSCSI SAN Configuration Guide ESX 4.0 ESXi 4.0 vCenter Server 4.0, page 20.

By default, ESX/ESXi provides an extensible multipathing module called the Native Multipathing Plugin (NMP).

Generally, the VMware NMP supports all storage arrays listed on the VMware storage HCL and provides a default path selection algorithm based on the array type.