A company is planning to use the Amazon EC2 instances as web servers. Customers from around the world will use the web servers. Most customers will use the web servers only during certain hours of the

Deploying in multiple Availability Zones enhances fault tolerance and availability but does not directly optimize costs based on fluctuating demand.

An Auto Scaling group dynamically adjusts the number of EC2 instances based on demand, scaling out during peak hours and scaling in during off-peak hours, which minimizes costs by ensuring resources are only provisioned when needed.

A placement group is used for optimizing network performance between instances, not for cost reduction based on variable demand.

Deploying in private subnets is a security measure to restrict direct internet access, and it does not reduce operational costs for fluctuating workloads.