Correct answer - "Create one CodePipeline for your entire flow, and add a manual approval step" :
You can add an approval action to a stage in an AWS CodePipeline pipeline at the point where you
want the pipeline to stop so someone can manually approve or reject the action.
Incorrect:
"Create multiple CodePipelines for each environment and link them using AWS Lambda" - You can
create Lambda functions and add them as actions in your pipelines but the approval step is
confined to a workflow process and not a different AWS service
"Create deeply integrated AWS CodePipelines for each environment" - You can use an AWS
CloudFormation template in conjunction with AWS CodePipeline and AWS CodeCommit to create a test
environment that deploys to your production environment when the changes to your application are
approved, helping you automate a continuous delivery workflow
"Use CodeDeploy Pipeline integrator" - In a pipeline CodeDeploy can be used as a deployment
action but it still requires a manual approval step to achieve the requirement