In the described AWS CI/CD pipeline, AWS CodeBuild is the service responsible for executing build and test commands. The pipeline is triggered and orchestrated by AWS CodePipeline, but the actual execution of the Snyk Command Line Interface (CLI) to scan the code occurs within a CodeBuild environment. CodeBuild runs the commands defined in a buildspec.yml file, which would include snyk test and snyk monitor. These CLI commands then interact with the Snyk service, sending scan results to the Snyk UI.

A. AWS CodeDeploy is a service for automating application deployments to various compute services. It is used after the build and test phase.

B. AWS CodeCommit is the source control repository. It stores the code and triggers the pipeline but does not execute build commands.

C. AWS CodePipeline is the orchestration service that defines the workflow stages (e.g., Source, Build, Deploy) but relies on other services like CodeBuild to perform the actions.

1. Snyk. (n.d.). Integrate with AWS CodePipeline. Snyk User Documentation. Retrieved from https://docs.snyk.io/integrations/ci-cd-integrations/aws-codepipeline-integration. The official integration guide shows a buildspec.yml file for AWS CodeBuild that contains the Snyk CLI commands.

2. Amazon Web Services. (n.d.). What Is AWS CodeBuild? AWS CodeBuild Documentation. Retrieved from https://docs.aws.amazon.com/codebuild/latest/userguide/welcome.html.

"AWS CodeBuild is a fully managed continuous integration service that compiles source code, runs tests, and produces software packages that are ready to deploy."