You are managing a legacy application Inside VPC with hard coded IP addresses in its configuration. Which two
mechanisms will allow the application to failover to new instances without the need for reconfiguration? (Choose two.)

A.
Create an ELB to reroute traffic to a failover instance

B.
Create a secondary ENI that can be moved to a failover instance

C.
Use Route53 health checks to fail traffic over to a failover instance

D.
Assign a secondary private IP address to the primary ENIO that can De moved to a failover instance

Explanation:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/MultipleIP.html#MultipleIPReqs