Which RAID level uses double parity Advanced Data Guarding?

A.
1

B.
5

C.
6

D.
10

Explanation:
Double-parity RAID (redundant array of independent disks), also called diagonal-parity RAID, Advanced Data
Guarding (RAID_ADG), or RAID-6, is a method of protecting against multiple storage drive failures by creating
two sets of parity data on an array of hard disks.
http://searchstorage.techtarget.com/definition/double-parity-RAID