Which of the following memory technologies has the HIGHEST cost to implement?

Error-Correcting Code (ECC) memory includes additional chips to detect and correct memory errors, adding a modest cost to individual RAM modules but not comparable to a full RAID implementation.

RAID (Redundant Array of Independent Disks) is a storage technology that combines multiple physical disk drives for data redundancy, performance, or both. Implementing RAID involves the acquisition of several physical drives and often a dedicated RAID controller card, which represents a significantly higher cost compared to features within individual memory modules.

Memory pairing, typically referring to configuring memory modules in pairs for dual-channel operation, is a design feature that does not inherently add significant cost beyond the initial purchase of compatible modules.

Registered (or buffered) memory includes a register on each module to stabilize signals for high-capacity systems, making it slightly more expensive than unbuffered memory but still a cost limited to the RAM modules themselves.