AWS Certified Solutions Architect Associate Test 2

Imho the idea for SQS is to improve scalability.
Elastic Beanstalk is checking the health of EC2 instances, not sure if SQS does.

D. SQS helps to facilitate horizontal scaling of encoding tasks.
Yes, this is a great scenario for SQS. "Horizontal scaling" means you have multiple instances involved in the workload (encoding tasks in this case). You can drop messages indicating an encoding job needs to be performed into an SQS queue, immediately making the job notification message accessible to any number of encoding worker instances.