Most of unplanned downtime of information systems is attributed to which of the following?

A.
Hardware failure

B.
Natural disaster

C.
Human error

D.
Software failure

Explanation:
This is what the static’s says. Most of the downtime is cause of unexpected hardware failure.
Commonly you just replace the FRU (Field replazable unit) when they fail. Usually a well written
software does not fail if the hardware is running correctly. The human errors are controllable and
natural disasters are not very often. Hardware failure is very common, it’s a good practice to have
spare disks, NIC and any other hardware FRU´s in your company to minimize the downtime with
quick replacements.