What are two reasons that would account for this problem?

A large amount of data was deleted from a volume. After a few hours, the space was still not available to NFS clients accessing the volume.

What are two reasons that would account for this problem? (Choose two.)
A . The client needs to re-scan the volume to detect the changes.
B . There is a thick-provisioned LUN in the volume.
C . The volume contains Snapshot copies that were taken before the data was deleted.
D . The deleted data was all deduplicated data.

Answer: AC