A company's internal web application currently runs on a single EC2 web server with a NAT instance for outbound internet access. The app must be made highly available. Which combination of architecture changes should be implemented? (Choose two.)

To achieve high availability for the web application, you need to distribute both the web servers and the outbound internet access across multiple Availability Zones (AZs). Launching additional EC2 web servers across multiple AZs and placing an Application Load Balancer (ALB) in front of them ensures that if one AZ or web server fails, traffic is automatically routed to healthy instances in other AZs. An ALB is ideal for HTTP/HTTPS traffic. Replacing the NAT instance with a NAT Gateway in each AZ provides a highly available and scalable solution for outbound internet access. NAT instances are single points of failure, whereas NAT Gateways are managed services that are highly available within an AZ. Updating route tables ensures traffic correctly flows through these new gateways. Placing an ALB in front of a single EC2 instance with CloudWatch alarms does not provide high availability; it only helps with recovery after a failure, leading to downtime. Putting the NAT instance into an Auto Scaling group is not a recommended or effective pattern for high availability of NAT services. A single NAT Gateway does not provide cross-AZ redundancy; if that AZ fails, outbound access is lost.