An organization has requested storage area network (SAN) disks for a new project. What Redundant Array of Independent Disks (RAID) level provides the BEST redundancy and fault tolerance?

RAID 1 provides mirroring across only two disks, which offers redundancy but sacrifices 50% of total storage capacity and does not scale as efficiently as RAID 5 for SAN environments with multiple disks.

RAID 3 uses byte-level striping with a dedicated parity disk, which creates a write bottleneck since all write operations must update the single parity disk, making it less fault-tolerant and performant than RAID 5.

RAID 4 uses block-level striping with a dedicated parity disk, similar to RAID 3, but the single dedicated parity disk still represents a performance bottleneck and a potential single point of failure during rebuilds, offering inferior fault tolerance compared to RAID 5's distributed parity.

RAID 5 stripes data and parity information across three or more disks, allowing the array to reconstruct data if any single disk fails without losing any data. Unlike RAID 1, it achieves fault tolerance without dedicating half the total capacity to mirroring, making it more efficient. In a SAN context, RAID 5 provides the best combination of redundancy, fault tolerance, read performance, and usable storage capacity among the options listed.