A way to assure data at-rest is secure even in the event of loss or theft is to use:

A.
Full device encryption.

B.
Special permissions on the file system.

C.
Trusted Platform Module integration.

D.
Access Control Lists.

Explanation:
Device encryption encrypts the data on the device. This feature ensures that the data on the
device cannot be accessed in a useable form should the device be stolen.