Which of the following is a key characteristic of battery-backed cache in RAID controllers?

A key characteristic of battery-backed cache in RAID controllers is that it prevents data loss during power outages. This technology is designed to protect the cached data that is being processed in the RAID array. When a server experiences an unexpected power loss, any data in transit, which would normally be lost, can instead be preserved by the battery-backed cache.

The battery provides power to the cache memory for a limited time, allowing the RAID controller to write any cached data to the underlying storage media when power is restored. This ensures data integrity and avoids corruption, maintaining the reliability of the RAID configuration.

In contrast, while enhancing data retrieval speeds, increasing processing speed, or reducing the need for memory upgrades can be benefits of other caching technologies or components, they do not specifically address the primary purpose of battery-backed cache. Its main function is specifically to safeguard data during power interruptions, making option A the most accurate choice.