Which of the below mentioned options is the right instance type and costing model in this case if the user performs the same task for the whole year?

A user is running a batch process which runs for 1 hour every day.

Which of the below mentioned options is the right instance type and costing model in this case if the user performs the same task for the whole year?
A . EBS backed instance with on-demand instance pricing.
B . EBS backed instance with heavy utilized reserved instance pricing.
C . EBS backed instance with low utilized reserved instance pricing.
D . Instance store backed instance with spot instance pricing.

Answer: A

Explanation:

For Amazon Web Services, the reserved instance helps the user save money if the user is going to run the same instance for a longer period. Generally if the user uses the instances around 30-40% annually it is recommended to use RI. Here as the instance runs only for 1 hour daily it is not recommended to have RI as it will be costlier. The user should use on-demand with EBS in this case.

Reference: http://aws.amazon.com/ec2/purchasing-options/reserved-instances/