What is a possible reason for this issue?

An EMC Avamar backup administrator has deleted several older backups that are no longer needed in an effort to gain more space for new backups. The delete operation succeeds. However, the administrator notices that the capacity utilization has not decreased.

What is a possible reason for this issue?
A . Avamar server is read-only due to lack of capacity
B . Backup storage is at 80% of user capacity
C . Garbage collection has not yet run
D . Backups are currently being replicated

Answer: C