Which of the following statements is true regarding RAID levels?

The statement that some RAID levels are redundant while others are not is accurate because different RAID configurations serve different purposes and utilize redundancy in various ways.

For instance, RAID 1 (mirroring) and RAID 5 (striping with parity) are designed to provide redundancy; they ensure that data is still accessible even if one or more disks fail. RAID 1 duplicates the same data on two disks, whereas RAID 5 distributes parity information across all disks, allowing for data recovery in the event of a single disk failure.

On the other hand, not all RAID configurations are focused on redundancy. For example, RAID 0 strips data across multiple disks without any parity or mirroring, which maximizes performance and storage capacity but does not provide any fault tolerance. If a single drive fails in a RAID 0 setup, all data is lost, indicating a lack of redundancy.

Thus, the correct answer reflects the variance among RAID levels in terms of their approach to data redundancy and fault tolerance.