Jonah recently adopted a method to back up his data to an external hard disk.

A Differential Backup copies all data changed since the last full backup, growing larger each time as more changes accumulate, matching Jonah’s observation of increasing storage use.

Option B (Online Data Backup):A delivery method, not a type.

Option C (Incremental Backup):Only backs up changes since the last backup, not growing as much.

Option D (Full System Backup):Copies everything, consistently large, not incremental growth.

“Differential Backups expand daily by capturing all changes since the last full backup, increasing storage needs with each run” (Module: Data Backup and Recovery, Section: Backup Types).