You host several virtual machines on a Windows Server 2008 R2 Hyper-V failover cluster. You are deploying a highly available virtual machine （HAVM） that supports live migration. You need to install the operating system in the appropriate location. What are two possible locations that will allow you to achieve this goal？（） 

• A、a VHD on network-attached storage （NAS）
• B、a VHD on an iSCSI logical unit number （LUN）
• C、a pass-through disk on direct-attached storage （DAS）
• D、a pass-through disk on a Fibre Channel logical unit number （LUN）