Concept:Preventing file loss means keeping extra copies of files to restore them later if needed.
Explanation:File backup involves copying files and storing them in a safe, separate place.
If the original files are deleted, corrupted, or damaged, the backup can be used to recover them.
File conversion changes file formats but does not protect against loss.
File maintenance helps organise files but does not guarantee recovery.
File sorting only arranges files in a particular order and cannot restore lost data.
Therefore, file backup is the operation that prevents file loss.
Answer:A. File backup