A host with 30 VMs has 64GB of RAM, four quad-core CPUs, four 1-gigabit NICs and is connected to a NAS that provides NFS volumes. The hosted VMs are reporting slow performance. From the information given, which of the following is the MOST likely cause of the slow performance?

A.
Insufficient NAS capacity

B.
The server is using 110V instead of 220V

C.
One hard drive has failed in the RAID 5

D.
Insufficient network capacity