Your organization has decided to implement a third-party configuration management tool that uses a master server from which nodes pull configuration. You have built a custom base Amazon Machine Image that already has the third-party configuration management agent installed. You want to use the same base AMI in Development, Test and Production environments, each of which has its own master server.
How should you configure your Amazon EC2 instances to register with the correct master server on launch?

A. Create a tag for all instances that specifies their environment. When launching instances, provide an Amazon EC2 UserData script that gets this tag by querying the MetaData Service and registers the agent with the master.
B. Use Amazon CloudFormation to describe your environment. Configure an input parameter for the master server hostname/address, and use this parameter within an Amazon EC2 UserData script that registers the agent with the master.
C. Create a script on your third-party configuration management master server that queries the Amazon EC2 API for new instances and registers them with it.
D. Use Amazon Simple Workflow Service to automate the process of registering new instances with your master server. Use an Environment tag in Amazon EC2 to register instances with the correct master server.