A developer must deploy the same Elastic Beanstalk application (using an Application Load Balancer) in three AWS Regions via CloudFormation, and use AWS Certificate Manager (ACM) to supply SSL certificates for each ALB. What is the correct way to provide certificates for each ALB?

ACM certificates are regional resources. To use an SSL certificate with an Application Load Balancer in a specific AWS Region, you must request or import that certificate within the same Region. Therefore, for deployments across three different Regions, a separate certificate needs to be requested in ACM for each Region and then associated with the respective ALB in that Region. Requesting a certificate in a single Region and attempting to import it or use it globally will not work because ACM certificates are not globally available or transferable between Regions. Even certificates requested in us-east-1 are still regional to us-east-1 and cannot be directly used in other Regions for services like ALBs.