You have a two-tier web application running two EC2 instances in a single Availability Zone in us-east-1. You need to move one of those instances to a different Availability Zone. Which approach will accomplish this?

Creating an Amazon Machine Image (AMI) from the existing EC2 instance is the correct approach because an AMI captures the exact state of the instance, including the operating system, applications, and data. This allows you to launch a new, identical instance in a different Availability Zone. Once the new instance is verified, the original can be safely terminated. Copying an EC2 instance directly to a different Availability Zone is not a native AWS feature. Moving an EC2 instance using the AWS CLI is also not possible as instances are tied to their launch Availability Zone. Stopping an instance and attempting to modify its Availability Zone is not an option; an instance's Availability Zone cannot be changed after creation.