The correct choice is Amazon Machine Image (AMI). You create an AMI from the existing EC2 instance and copy that AMI to the target Region so you can launch identical instances there.

Amazon Machine Image (AMI) packages the instance root volume and launch metadata into a bootable image that can be copied between Regions. After you copy the AMI to us-west-2 you can use it to start EC2 instances with the same configuration as the original.

AWS CloudFormation can deploy infrastructure from templates but it does not replicate AMIs across Regions. You still need an AMI that exists in the destination Region for a CloudFormation template to reference.

AWS Lambda is a serverless compute service and it is not used to create or duplicate EC2 machine images.

Amazon EBS snapshots capture the state of volumes and you can copy snapshots across Regions but a snapshot by itself is not a registered bootable image. You would still create or register an AMI to launch the same instance from snapshot data.

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