Which is the most appropriate EBS Volume Type for this …

You are designing an enterprise data storage system. Your data management software system requires mountable disks
and a real filesystem, so you cannot use S3 for storage. You need persistence, so you will be using AWS EBS Volumes
for your system. The system needs as low-cost storage as possible, and access is not frequent or high throughput, and
is mostly sequential reads. Which is the most appropriate EBS Volume Type for this scenario?

A.
gp1

B.
io1

C.
standard

D.
gp2

Explanation:
standard volumes, or Magnetic volumes, are best for: Cold workloads where data is infrequently accessed, or scenarios
where the lowest storage cost is important.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html