Which of the below mentioned options can help achieve fault tolerance?

A user has attached 1 EBS volume to a VPC instance. The user wants to achieve the best fault tolerance of data possible.

Which of the below mentioned options can help achieve fault tolerance?
A . Attach one more volume with RAID 1 configuration.
B . Attach one more volume with RAID 0 configuration.
C . Connect multiple volumes and stripe them with RAID 6 configuration.
D . Use the EBS volume as a root device.

Answer: A

Explanation:

The user can join multiple provisioned IOPS volumes together in a RAID 1 configuration to achieve better fault tolerance. RAID 1 does not provide a write performance improvement; it requires more bandwidth than non-RAID configurations since the data is written simultaneously to multiple volumes.

Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/raid-config.html