RAID 1, also known as mirroring, involves copying (or mirroring) data to two drives simultaneously to ensure data integrity in case one drive fails. This is the best option for the scenario described because it provides redundancy for critical business data without requiring complex configurations or more than two drives. RAID 0, while improving performance through striping, offers no redundancy. RAID 5 requires a minimum of three drives and offers both performance and redundancy, but it is more complex than necessary for two drives. RAID 10 also offers redundancy but requires at least four drives to implement the combined features of RAID 1 and RAID 0.