In an EMC Data Domain Archiver system, what is a characteristic of a sealed archive unit?

A.
Data from the archive unit can be recovered even if the other units in the same system are lost
B.
A sealed archive unit is marked as read-only; writes and file deletions are not permitted
C.
Unit needs to be manually put into an online mode if recovery of data is necessary
D.
Data in the sealed unit is not replicated for security reasons