In this scenario, why is storage efficiency reduced after replication?

You have a FAS9000 with 10 TBNL-SAS drives that is replicating to a FAS8200 with 4 TB NL-SAS drives. An 80 TB source volume on the FAS9000 is showing 50% storage efficiency. After that volume mirror is initialized, the FAS8200 destination volume is showing only 10% storage efficiency.

In this scenario, why is storage efficiency reduced after replication?
A . The different controller models require logical replication.
B . The different sized drives use different efficiency methods.
C . The source volume has inline deduplication enabled.
D . The destination volume has post process compression enabled.

Answer: B