Final answer:
To increase data availability in a cost-effective manner, using RAID, especially RAID 1, for redundancy and incremental backups for saving on storage costs are the best choices for adding fault-tolerance capabilities.
Step-by-step explanation:
To add fault-tolerance capabilities within a business with the objective of increasing the availability of data while keeping costs low, the best choice would likely involve using redundant systems and data backup solutions that are cost-effective.
A common and budget-friendly option is RAID (Redundant Array of Independent Disks). RAID can combine multiple cheaper disks into an array to improve performance and provide redundancy. If a disk fails, the system can continue operating with little to no downtime.
RAID 1, also known as mirroring, duplicates the data across two disks, and it's an excellent starting point for fault tolerance.
Another cost-effective solution is implementing incremental backups, where only the changes since the last backup are stored, thus saving on storage costs.