Answer - C and D.
Since the only requirement is that the infrastructure should maintain its full capacity, So answers should be both C &
D.You can now use an immutable deployment policy when updating your application or environment configuration on Elastic Beanstalk.
This policy is well suited for updates in production environments where you want to minimize downtime and reduce the risk from failed deployments.
It ensures that the impact of a failed deployment is limited to a single instance and allows your application to serve traffic at full capacity throughout the update.
You can now also use a rolling with additional batch policy when updating your application.
This policy ensures that the impact of a failed deployment is limited to a single batch of instances and allows your application to serve traffic at full capacity throughout the update.
Option A is incorrect because All at once is used to deploy the new version to all instances simultaneously.
All instances in your environment are out of service for a short time while the deployment occurs.
Option B is incorrect because Rolling is used to deploy the new version in batches.
Each batch is taken out of service during the deployment phase, reducing your environment's capacity by the number of instances in a batch.