An application runs on a set of Amazon EC2 instances behind an Elastic Load Balancer and is managed by an Auto Scaling group. For most of the day performance is stable, but each day there is the same 4-hour spike in traffic that degrades performance. Which solution is the MOST operationally efficient way to address the recurring slowdown?

A scheduled Auto Scaling action is the most operationally efficient solution because it automates the scaling process based on a predictable schedule. This ensures that additional capacity is available before the traffic spike occurs, preventing performance degradation without manual intervention. Putting a second Elastic Load Balancer in front of the Auto Scaling group and using weighted routing is unnecessary and adds complexity without directly addressing the need for more compute capacity. Switching to larger EC2 instance types would resolve the performance issue but is less cost-effective, as the larger instances would be over-provisioned for the majority of the day when traffic is stable. Manually launching and attaching instances is not operationally efficient; it requires constant monitoring and manual intervention, which is prone to human error and delays.