A company needs to optimize costs for an AWS environment that uses multiple accounts under AWS Organizations. Three years ago the company bought EC2 Standard Reserved Instances that recently expired. The company expects to need EC2 compute for another 3 years and has also deployed a new serverless workload. Which purchasing strategy gives the MOST cost savings?

The correct option provides the most cost savings because All Upfront payments offer the largest discount for both Reserved Instances (RIs) and Savings Plans. RIs are suitable for predictable, long-term EC2 usage, and renewing them for another 3 years with All Upfront maximizes savings for the existing EC2 workload. A 3-year All Upfront Compute Savings Plan, purchased in the management account, covers the new serverless workload (which can be Fargate, Lambda, or EC2 instances) and any additional EC2 usage across all accounts, providing flexibility and further discounts. Incorrect options: 1-year No Upfront Savings Plans offer smaller discounts and require more frequent renewals, increasing administrative overhead. Purchasing them per member account also prevents aggregation of usage for better discounts. EC2 Instance Savings Plans are less flexible than Compute Savings Plans as they only apply to EC2 instances, not serverless compute. No Upfront payments offer lower discounts. Purchasing EC2 Instance Savings Plans per member account prevents the aggregation of usage across the organization, leading to lower overall discounts.