Which two statements are correct?

Compare a typical Distributed Replicated Block Device (DRBD) with MySQL Standard
Replication using master-slave replication. Which two statements are correct?

A.
Both technologies guarantee an identical copy of data on the secondary node.

B.
Only MySQL can maintain a time-delayed copy of data on the secondary node.

C.
Both technologies use the TCP/IP stack as their primary transmission medium.

D.
DRBD uses shared-disk technology.