As a Site Reliability Engineer (SRE) tasked with enhancing the deployment process through scaling and automation, you play a crucial role in ensuring the seamless release of new application versions into production. To achieve a smooth rollout, it is essential that these new versions are deployed incrementally across different sets of EC2 instances, thereby facilitating a gradual transition and minimizing potential disruptions.

Given the need to deploy application updates to multiple groups of EC2 instances at varying times for a smooth transition, which of the following features in AWS CodeDeploy enables this capability?