A company deploys a B2B service to dedicated infrastructure in each customer account. Before releasing a feature, the team must run integration tests on real test infrastructure (EC2 instances and an RDS database) across multiple AWS accounts. You need a continuous delivery process that provisions the test infrastructure in those accounts and then runs the integration tests with the LEAST administrative effort. Which solution meets this requirement?

The correct option leverages AWS CodePipeline for orchestrating the continuous delivery process. CodePipeline integrates with AWS CloudFormation change sets to preview and apply infrastructure changes across multiple accounts, ensuring controlled deployments. Using a CloudFormation custom resource allows for running integration tests directly within the CloudFormation deployment workflow, minimizing administrative overhead by keeping infrastructure provisioning and testing within a single, automated process. Incorrect options: AWS CodeDeploy is for application deployment, not infrastructure provisioning across multiple accounts. Amazon CodeGuru is for code review, not running integration tests. AWS CloudFormation StackSets are suitable for deploying infrastructure across multiple accounts, but AWS CodeBuild is better suited for running tests than being integrated directly into a StackSet. The question asks for the LEAST administrative effort. AWS SAM is for serverless applications and doesn't directly address the need for deploying EC2 and RDS infrastructure across multiple accounts in this context. AWS CodeDeploy is for application deployment, not running integration tests.