The answer would be the second choice, B. To protect data from accidental lost.
When you back up important data, you make a copy of your most important files; which can then be used if the original copy is lost. If you choose not to back up your own files, you risk losing important data. A few ways you can lose data:
- when your hard drive crashes (and they do crash)
- if you accidentally delete it or it becomes corrupt
- when a virus deletes or corrupts the file
You might also get a new computer and need to move your files, so having a backup is useful.