Answer – B and E
The AWS Documentation mentions the following.
Immutable deployments perform an immutable update to launch a full set of new instances running the new version of the application in a separate Auto Scaling group, alongside the instances running the old version. Immutable deployments can prevent issues caused by partially completed rolling deployments. If the new instances don`t pass health checks, Elastic Beanstalk terminates them, leaving the original instances untouched.
And with Blue Green deployments, you can have a separate deployment environment as well.
Option A is incorrect because All at once deployment deploys 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 C is incorrect because Rolling deployment deploys 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.
Option D is incorrect because there is no Linear deployments.
For more information on Deployment options, please refer to the below Links-
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.rolling-version-deploy.html
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.CNAMESwap.html