A company has a workflow that sends video files from their on-premise system to AWS for transcoding. They use EC2 worker instances to pull transcoding jobs from SQS. Why is SQS an appropriate service for this scenario?

Answer options:

A.SQS guarantees the order of the messages.
B.SQS synchronously provides transcoding output.
C.SQS checks the health of the worker instances.
D.SQS helps to facilitate horizontal scaling of EC2 worker instances when the queue grows.

Correct Answer - D
Even though SQS guarantees the order of messages for FIFO queues, the main reason for using it is that it helps in horizontal scaling of AWS resources and is used for decoupling systems. 
SQS can neither be used for transcoding output nor for checking the health of worker instances. The health of worker instances can be checked via ELB or CloudWatch.
For more information on SQS, please visit the following URL- 
https://aws.amazon.com/sqs/faqs/