Answer:
one disk
Explanation:
RAID 5:is an independent disks configuration of redundant array that utilizes disk striping in addition to parity. Data and parity bits are striped uniformly across the entire the disks configuration, so that no any single disk can create a bottleneck.
"Today one disk has failed in this RAID. How many disks do you replace"
Since RAID 5 guard against data through implementation of stripping of both data and parity bits, the failed disk can be replaced to restore the company's RAID 5 array fully back into service.