A North American company with headquarters on the East Coast is deploying a web application in us-east-1 (primary). The application must scale dynamically, be resilient, and support an active-passive disaster recovery configuration with us-west-1 (standby). After creating a VPC in us-east-1, what steps should the solutions architect take to meet these requirements?

The correct option establishes an active-passive disaster recovery strategy using Route 53 failover routing. An ALB and Auto Scaling Group (ASG) across multiple Availability Zones (AZs) in both us-east-1 and us-west-1 ensures high availability and scalability within each region. Route 53 health checks monitor the primary region (us-east-1), and upon failure, traffic is automatically routed to the standby region (us-west-1). The first incorrect option proposes an Auto Scaling Group spanning both VPCs and served by a single ALB, which is not a standard or efficient cross-region deployment model for an active-passive setup. The third incorrect option suggests an ALB spanning both VPCs via inter-Region VPC peering, which is not how ALBs function; ALBs are regional. The fourth incorrect option describes a similar setup but instead of a single Route 53 failover record set, it suggests separate Route 53 records in each region, which would require more complex management for failover.