A. A level 1 backup which is then merged with the save set’s last full backup creating a new full backup.
B. A level 9 backup which is then merged with the save set’s last full backup creating a new full backup.
C. A level Full backup which is then merged with the save set’s last full backup creating a new full backup.
D. An Incremental level backup which is then merged with the save set’s last full backup creating a new full backup.