Route 53 is a DNS managed by AWS, but nothing prevents you from running your own DNS (it's just a
software) on an EC2 instance. The trick of this question is that it's about EC2, running some
software that needs a fixed IP, and not about Route 53 at all.
Correct answer - "Elastic IP" : DNS services are identified by a public IP, so you need to use
Elastic IP.
"Create a Load Balancer and an auto scaling group" - Load balancers do not provide an IP, instead
they provide a DNS name
"Provide a static private IP" - If you provide a private IP it will not be accessible from the
internet
"Use Route 53" - Route 53 is a DNS service but here it is offering a DNS service using an EC2
instance