In order to provide additional protection to a RAID group, which of the following should the administrator use?

Distributed parity is a feature of RAID levels like RAID 5 or RAID 6, where parity information is spread across all disks, which provides the primary fault tolerance, not additional protection on top of a RAID group.

A cold spare is a replacement disk that is not powered on and must be manually installed and configured after a disk failure, which delays the rebuild process and doesn't offer immediate, automatic protection.

Dedicated parity refers to a specific disk or disks solely used for parity information (e.g., RAID 4), which provides primary fault tolerance, not additional protection in the context of a hot spare.

A hot spare disk is an unassigned disk that is kept powered on and ready to automatically replace a failed disk in a RAID array. When a disk fails, the RAID controller immediately begins rebuilding the data onto the hot spare, minimizing the time the array operates in a degraded state and reducing the risk of further data loss if another disk fails.