You are configuring an Auto Scaling group for an application. The fleet must maintain 50% spare CPU capacity at all times to handle sudden spikes. Traffic rises substantially from 09:00 to 17:00 every day. How should you configure scaling to meet these requirements?

The correct option combines proactive and reactive scaling. A target tracking policy set at 50% CPU utilization ensures that the Auto Scaling group maintains 50% spare capacity, as it will scale out when the used capacity (CPU utilization) exceeds 50%. This directly addresses the requirement for spare capacity. The scheduled policies handle the predictable daily traffic surge, ensuring instances are provisioned before the peak starts at 09:00 and scaled down after 17:00, optimizing costs. A target tracking policy at 90% CPU utilization would not maintain 50% spare capacity; it would only scale when the system is nearly fully utilized. Fixing capacity to 2 instances is not dynamic and won't handle varying loads or maintain spare capacity. Relying solely on scheduled policies without a target tracking policy would not react to unexpected spikes or sustained load changes within the scheduled periods.