A Developer migrated a web application to AWS. As part of the migration, the Developer implemented an automated continuous integration/continuous improvement (CI/CD) process using a blue/green deployment. The deployment provisions new Amazon EC2 instances in an Auto Scaling group behind a new Application Load Balancer. After the migration was completed, the Developer began receiving complaints from users getting booted out of the system. The system also requires users to log in after every new deployment.
How can these issues be resolved?

A. Use rolling updates instead of a blue/green deployment
B. Externalize the user sessions to Amazon ElastiCache
C. Turn on sticky sessions in the Application Load Balancer
D. Use multicast to replicate session information