What does the ‘Swap Environment URLs’ feature aid most directly when thinking of AWS Elastic Beanstalk?

Answer options:

A.Immutable Rolling Deployments
B.Mutable Rolling Deployments
C.Canary Deployments
D.Blue-Green Deployments

Answer – D
The AWS Documentation mentions the following.
Because Elastic Beanstalk performs an in-place update when you update your application versions, your application may become unavailable to users for a short period of time. It is possible to avoid this downtime by performing a blue/green deployment, where you deploy the new version to a separate environment and then swap CNAMEs of the two environments to redirect traffic to the new version instantly.
Blue/green deployments require that your environment runs independently of your production database, if your application uses one. If your environment has an Amazon RDS DB instance attached to it, the data will not transfer over to your second environment. They will be lost if you terminate the original environment.
For more information on Blue/Green deployments with AWS, please visit the link –
http://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features.CNAMESwap.html