A server has five hot pluggable SCSI disk drives in a RAID 5 array. The server OS crashed and the server will not boot. The administrator noticed that all of the disk drives have gone offline. Which…

Memory failure typically causes system crashes, bluescreens, or boot failures, but it would not specifically cause all physical disk drives to simultaneously go offline.

The SCSI backplane is a shared hardware component connecting all hot-pluggable SCSI drives to the server's RAID controller; if the backplane fails, it will cause all attached drives to simultaneously go offline, preventing the server from booting.

While individual SCSI drives can fail in a RAID 5 array, it is extremely unlikely for all five drives to fail simultaneously and completely go offline, suggesting a shared component failure.

A motherboard failure would prevent the server from booting, but a specific symptom of 'all disk drives gone offline' points more directly to an issue with the drive's communication path rather than a general motherboard failure.