A new 5 MB file was backed up by Time Machine yesterday. Today the file was edited, and has grown to 6 MB. It is about to be backed up by Time Machine again.
How does Time Machine perform this backup?

A.
Time Machine copies the 6 MB file to the backup drive, and deletes the original backup copy of the file from the backup drive.

B.
Time Machine copies the 6 MB file to the backup drive, and keeps both the new backup file and the original backup file on the backup drive.

C.
Time Machine identifies the 1 MB of file changes, copies those changes to a new file on the backup drive, and keeps both the new backup file and the original
backup file.

D.
Time Machine identifies the 1 MB of file changes, copies those changes to a new file on the backup drive, then creates a 500 KB parity file, and keeps all three
files: the two new files representing the 1 MB of file changes, and the original backup file.