What is an appropriate configuration for a highly avail…

A client application requires operating system privileges on a relational database server. What
is an appropriate configuration for a highly available database architecture?

A.
A standalone Amazon EC2 instance

B.
Amazon RDS in a Multi-AZ configuration

C.
Amazon EC2 instances in a replication configuration utilizing a single Availability Zone

D.
Amazon EC2 instances in a replication configuration utilizing two different Availability Zones

Explanation:
http://docs.aws.amazon.com/dms/latest/userguide/CHAP_Introduction.ReplicationInstance.ht
ml