Which solution will make the application highly available?
Provision a subnet in each Availability Zone. Configure the Auto Scaling group to distribute the EC2 instances across both Availability Zones. Configure the DB instance with connections to each network.
Provision two subnets that extend across both Availability Zones. Configure the Auto Scaling group to distribute the EC2 instances across both Availability Zones. Configure the DB instance with connections to each network.
Provision a subnet in each Availability Zone. Configure the Auto Scaling group to distribute the EC2 instances across both Availability Zones. Configure the DB instance for Multi-AZ deployment.
Provision a subnet that extends across both Availability Zones. Configure the Auto Scaling group to distribute the EC2 instances across both Availability Zones. Configure the DB instance for Multi-AZ deployment.
Explanations:
The DB instance cannot be configured with connections to each network in separate Availability Zones. This solution does not provide a Multi-AZ RDS setup.
Subnets cannot extend across Availability Zones. Each subnet must be in a specific Availability Zone. This option lacks the necessary Multi-AZ DB configuration.
Provisioning a subnet in each Availability Zone and configuring the Auto Scaling group to distribute EC2 instances ensures high availability. The Multi-AZ RDS configuration ensures DB failover across AZs.
Subnets cannot extend across Availability Zones. A subnet must reside in a single Availability Zone, and this option does not address DB Multi-AZ configuration properly.
I sort that the answer is:
Provision a subnet in each Availability Zone. Configure the Auto Scaling group to distribute the EC2 instances across both Availability Zones. Configure the DB instance for Multi-AZ deployment.