Identify the correct pair from the following:

Concept

Computing terms and abbreviations fall into distinct functional categories — a multimedia file format, an application program, a storage hardware device, and an operating system each serve a different role. Correctly pairing a term with its category means matching it to what it was actually built to do, not to a category it merely sounds close to.

Applying it here

Ubuntu is a Linux-based operating system: it is the core system software that manages a computer's hardware resources (processor, memory, storage) and provides the platform on which all other application software runs. That is exactly the role of an operating system, so the pair "Ubuntu - Operating System" is correctly matched.

Contrasting the other pairs

• AVI (Audio Video Interleave) is a multimedia container format used to store synchronized audio and video data — it has nothing to do with transferring files across a network; that role belongs to a protocol such as FTP.

• Excel is spreadsheet software built for numerical data, formulas, and calculations — it is not a word-processing program, a role served by document editors designed for typing and formatting text.

• An HDD (Hard Disk Drive) is a physical storage device fitted inside or attached to a computer — it stores data locally, unlike cloud storage, which keeps data on remote servers accessed over the internet.

Result

Only one of the four listed items is paired with the category it truly belongs to — the operating system pairing. The other three each name a term correctly but attach it to the wrong category.