Which RAID level uses double distributed parity?

A.
1
B.
3
C.
5
D.
6
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