A technician is diagnosing a computer receiving the following message upon boot: "RAID degraded." Which of the following is MOST likely the cause of such an issue?

Faulty RAM produces memory errors, blue screens, or random crashes but does not affect RAID controller status or generate a RAID-specific boot message.

A faulty RAID battery backup unit (BBU) affects the write-back cache and would generate a cache or BBU warning, not a 'RAID degraded' message.

A faulty power supply may cause random shutdowns or power instability but would not specifically generate a 'RAID degraded' status message from the controller.

RAID arrays monitor the health of all member drives; when a drive fails or becomes unresponsive, the RAID controller marks the array as 'degraded' because it can no longer maintain full parity or mirroring. The system can often still operate in degraded mode (depending on RAID level), but data is at risk until the faulty drive is replaced and the array is rebuilt.