You have an application that analyzes images within files. For each of the files in the input stream, the application writes to some number of output files. The number of input files processed each day is high and concentrated within a few hours of the day.

Answer options:

A.Use S3 to store the files. Use SQS to store the elaboration commands. Configure an Auto Scaling group to process the messages in the queue and dynamically adjust the size of the group depending on the length of the SQS queue.
B.Use EBS with Provisioned IOPS (PIOPS) to store I/O files. Use SNS to distribute elaboration commands to a group of hosts working in parallel and Auto Scaling to dynamically size the group of hosts depending on the number of SNS notifications.
C.Use S3 to store I/O files and SNS to distribute elaboration commands to a group of hosts working in parallel. Auto Scaling to dynamically size the group of hosts depending on the number of SNS notifications.
D.Use EBS with Provisioned IOPS (PIOPS) to store I/O files. Use SQS to distribute elaboration commands to a group of hosts working in parallel. Use Auto Scaling to dynamically size the group of hosts depending on the length of the SQS queue.

Answer – A
The scenario in this question is that (a) there are EC2 instances that need to process a high number of input files, (b) currently the processing takes 20 hrs a day, which needs to be reduced, (c) the availability needs to be improved.
First, let`s see whether we should choose S3 or EBS with PIOPS. It appears that all the options have auto-scaling in common. There will be multiple EC2 instances working in parallel on the input data. This should reduce the overall elaboration time, satisfying one of the requirements.
You can enable Multi-Attach on Amazon EBS Provisioned IOPS io1 volumes to allow a single volume to be concurrently attached to up to sixteen AWS Nitro System-based Amazon Elastic Compute Cloud (Amazon EC2) instances within the same Availability Zone which does not guarantee the availability. Whereas S3 provides high availability, which satisfies the other requirements. 
Second, SQS is a great option to do autonomous tasks and can queue service requests, and can be scaled to meet the high demand. SNS is a mere notification service and would not hold the tasks. Hence, SQS is certainly the correct choice. 
Option A is CORRECT because, as mentioned above, it provides high availability and can store a massive amount of data. Auto-scaling of EC2 instances reduces the overall processing time and SQS helps distribute the commands/tasks to EC2 instances.
Option B is incorrect because, as mentioned above, neither EBS nor SNS is a valid choice in this scenario.
Option C is incorrect because, as mentioned above, SNS is not a valid choice in this scenario.
Option D is incorrect because, as mentioned above, EBS is not a valid choice in this scenario.