Which combination of steps should a solutions architect take to provide high availability for this architecture?
(Choose two.)
Create new public and private subnets in the same AZ for high availability.
Create an Amazon EC2 Auto Scaling group and Application Load Balancer spanning multiple AZs.
Add the existing web application instances to an Auto Scaling group behind an Application Load Balancer.
Create new public and private subnets in a new AZ. Create a database using Amazon EC2 in one AZ.
Create new public and private subnets in the same VPC, each in a new AZ. Migrate the database to an Amazon RDS multi-AZ deployment.
Explanations:
Creating new subnets in the same AZ does not provide high availability because it does not protect against AZ failures.
An Auto Scaling group and Application Load Balancer across multiple AZs ensure that the web application can scale and remain accessible even if an AZ fails.
Adding existing instances to an Auto Scaling group and Load Balancer in one AZ does not provide high availability, as it does not cover AZ failure scenarios.
Creating a database on Amazon EC2 in one AZ does not provide high availability, as it lacks redundancy and resilience to AZ failure.
Deploying public and private subnets across multiple AZs and migrating the database to an RDS multi-AZ setup provides high availability and redundancy for the database.
I believe the answer is:
Create an Amazon EC2 Auto Scaling group and Application Load Balancer spanning multiple AZs.