Which of the below mentioned pricing models should the user choose in this case?

A user needs to run a batch process which runs for 10 minutes. This will only be run once, or at maximum twice, in the next month, so the processes will be temporary only. The process needs 15 X-Large instances. The process downloads the code from S3 on each instance when it is launched, and then generates a temporary log file. Once the instance is terminated, all the data will be lost.

Which of the below mentioned pricing models should the user choose in this case?
A . Spot instance.
B . Reserved instance.
C . On-demand instance.
D . EBS optimized instance.

Answer: A

Explanation:

In Amazon Web Services, the spot instance is useful when the user wants to run a process temporarily. The spot instance can terminate the instance if the other user outbids the existing bid. In this case all storage is temporary and the data is not required to be persistent. Thus, the spot instance is a good option to save money.

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