What is a characteristic of an EMC Avamar NDMP backup?

What is a characteristic of an EMC Avamar NDMP backup?
A . After the first level 0 backup, level 1 backups are performed and merged to a full backup.
B . Every backup is a level 0 backup.
C . Level 1 backups are performed daily and merged to a full backup at the end of the week.
D . Each backup is a level 1 backup, and is merged to a full backup only when a restore request is received.

Answer: A