What is a consideration when enabling encryption at rest?

A customer is performing backups of then dosktoplaptop client to a Dell EMC Avamar server. They plan to add a secure Oracle database server as a new backup client However, they are concerned about the security of the database data since no data is being one encrypted when it is stored on the Avamar server.

What is a consideration when enabling encryption at rest?
A . Only new client will have encrypted data
B . Amount of storage capacity will be reduced
C . Desktop/laptop backups will become inaccessible
D . Only database data will be encrypted

Answer: D