Reserved Instances would be the most appropriate choice for the company because they provide a significant discount compared to On-Demand pricing, in exchange for a commitment to use the instance for either a one- or three-year term. This upfront commitment aligns well with the company's requirement to run the workload heavily for one year. Spot Instances, while offering even lower prices, are not suitable for predictable and steady-state workloads since they can be interrupted by AWS with a two-minute notification if the capacity is needed back. Savings Plans are close but would require more complexity in managing commitments across different instance families or regions, whereas a Reserved Instance can directly reflect their exact needs.