A company wants to migrate an application to AWS and increase the application's availability. The company also wants to use AWS WAF in the application's architecture. Which solution meets these requirements?

This solution correctly addresses all requirements. An Auto Scaling group across multiple Availability Zones with an ALB provides high availability and scalability. The ALB distributes traffic to the EC2 instances. AWS WAF integrates directly with Application Load Balancers to protect web applications from common exploits. The second option is incorrect because a cluster placement group is for low-latency EC2 instances within a single Availability Zone, not for high availability across zones, and WAF cannot be connected to a placement group. The third option lacks scalability and automatic recovery, as it uses only two fixed EC2 instances without an Auto Scaling group. The fourth option is incorrect because AWS WAF cannot be directly connected to an Auto Scaling group; it must be associated with a resource like an ALB.