Auto Scaling is the correct answer because it allows applications to adjust capacity automatically to maintain steady and predictable performance at the lowest possible cost. During periods of low usage, resources can be scaled down, and during spikes, such as weekends in the provided scenario, resources can be scaled up to handle the increased load. Elastic Load Balancing distributes incoming traffic across multiple targets, such as EC2 instances, but does not handle scaling of resources. Multi-AZ deployment improves availability and fault tolerance but does not automatically adjust capacity to manage fluctuating workloads. Provisioned IOPS are used to specify performance characteristics of EBS volumes but do not provide scaling of computing resources.