Which policy or resource should the company use to meet these requirements?
An Amazon Route 53 simple routing policy
An Amazon Route 53 multivalue answer routing policy
An Application Load Balancer in one Region with a target group that specifies the EC2 instance IDs from both Regions
An Application Load Balancer in one Region with a target group that specifies the IP addresses of the EC2 instances from both Regions
Explanations:
A Route 53 simple routing policy is not suitable for multi-Region deployments. It directs traffic to one single resource without considering health checks or multi-Region redundancy.
A Route 53 multivalue answer routing policy can route traffic across multiple resources, supports health checks, and distributes traffic only to healthy Regions, which is ideal for disaster recovery and growth.
An Application Load Balancer (ALB) cannot span multiple Regions and cannot distribute traffic across Regions. ALBs are designed to route traffic only within a single Region.
Using an ALB in one Region with a target group of IP addresses from both Regions is not recommended because ALBs do not support cross-Region load balancing. This setup cannot ensure high availability across Regions.
I arrange that the answer is:
An Amazon Route 53 multivalue answer routing policy