Your company has a set of EBS volumes and a set of adjoining EBS snapshots. They want to minimize the costs for the underlying EBS snapshots. Which of the following approaches provides the lowest cost for Amazon Elastic Block Store snapshots while giving you the ability to restore data fully?

Answer options:

A.Maintain two snapshots: the original snapshot and the latest incremental snapshot.
B.Maintain a volume snapshot; subsequent snapshots will overwrite one another
C.Maintain a single snapshot: the latest snapshot is both Incremental and complete.
D.Maintain the most current snapshot, archive the original and incremental to Amazon Glacier.

Answer – C
The AWS Documentation mentions the following.
You can back up the data on your Amazon EBS volumes to Amazon S3 by taking point-in-time snapshots. Snapshots are incremental backups, which means that only the blocks on the device have changed after your most recent snapshot is saved. This minimizes the time required to create the snapshot and saves on storage costs by not duplicating data. When you delete a snapshot, only the data unique to that snapshot is removed. Each snapshot contains all of the information needed to restore your data (from the moment when the snapshot was taken) to a new EBS volume.
For more information on EBS Snapshots, please refer to the below link-
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSSnapshots.html