How do ASM failure group provide redundancy?

A.
For external redundancy ASM disk groups are placed in a Raid 1+0 configuration to ensure the no blocks
are lost during an outage.

B.
They ensure that the ASM disks are accessed via ADB protocol and not physically mounted on the
database server.

C.
They assign ASM disks to failure groups to ensure that the mirror copies of a block are not in the same
failure group.

D.
They ensure that the cell disks are sliced into grid disks by using cellsrv processes.