Which refers to the process of moving a backup from one storage device to another,...

Staging is the recognized term for the process of relocating backup data from one storage tier or device to another, typically moving data from faster, more expensive disk-based storage down to a lower-cost, higher-capacity medium such as tape, and then removing the original copy from the source tier once the move is complete, effectively migrating the backup's residency rather than duplicating it. This distinguishes staging from a simple copy operation, since staging specifically involves the deliberate removal of the original after successful transfer, freeing up capacity on the source tier for new, incoming backup data. Cloning (B) refers to creating an independent, full duplicate of data, typically as a point-in-time local replication technique, and does not inherently involve removing the source data afterward, which is the opposite behavior from what the question describes. Multiplexing (C) refers to interleaving multiple concurrent backup data streams onto a single target device to improve throughput utilization during the backup write process, a technique unrelated to relocating and removing an already-completed backup afterward. Copying (D) generically describes duplicating data from one location to another while leaving the original intact, which does not satisfy the specific requirement that the original backup be removed after the move, distinguishing it from staging. Staging is correct.

Reference topic: Data Backup and Deduplication - Backup Staging Between Storage Tiers.