In an N8500 Clustered NAS System, Underlying Virtualization Is Implemented

In an N8500 clustered NAS system, underlying virtualization is implemented by the VxVM component. The virtual objects managed by the VxVM are VM disks, disk groups, subdisks, and plexes. Which of the following statements is incorrect?

A) A VM disk is controlled by the VxVM and typically located in a disk group. Each VM disk corresponds to at least one physical disk or disk partition.
B) A disk group is a collection of VM disks.
C) A subdisk is the basic unit for the VxVM to allocate disk space. To improve the efficiency of underlying resource use, a subdisk can be a group of inconsecutive disk blocks.
D) A plex consists of one or multiple subdisks on one or multiple physical disks. Each plex contains a duplicate of the data selected in a volume.