Correct answer - "ELB" : Elastic Load Balancing automatically distributes incoming application
traffic across multiple targets, such as Amazon EC2 instances, containers, IP addresses, and
Lambda functions. Route 53 failover policy is similar to an ELB in that when using failover
routing, it lets you route traffic to a resource when the resource is healthy or to a different
resource when the first resource is unhealthy.
"CloudFront" - Allows you to distribute content with low latency and high data transfer rates
"S3" - Amazon S3 provides you a way to store and retrieve any amount of data
"Auto Scaling" - AWS Auto Scaling will automatically scale resources as needed to align to your
selected scaling strategy, so you maintain performance and pay only for the resources you
actually need
For more information visit
53/latest/DeveloperGuide/routing-policy.html