All servers on your network run Windows Server 2008 R2.  You plan to configure multiple highly available virtual machines （HAVMs） on a Hyper-V failover cluster. You need to recommend a storage solution that supports high availability.  Which storage solution should you recommend？（）

• A、a direct-attached storage （DAS） device
• B、a multipath serial-attached SCSI drive with a witness disk
• C、a multipath Fibre Channel logical unit number （LUN） with a witness disk
• D、a multipath iSCSI logical unit number （LUN） with Cluster Shared Volumes （CSVs）