What is the MOST cost-effective pricing model for this workload?

Explanations:

On-Demand Instances are billed at a variable rate per hour and are ideal for short-term workloads but are more expensive for long-term use compared to other options.

Reserved Instances offer significant cost savings (up to 75%) for workloads with a predictable usage pattern over a 1- or 3-year term, making them the most cost-effective choice for a 3-year workload.

Dedicated Instances provide physical servers dedicated to a single customer but come with higher costs and do not offer the same level of savings as Reserved Instances for a long-term workload.

Spot Instances allow users to bid on unused EC2 capacity at lower prices, but they can be terminated by AWS with little notice, making them unsuitable for stateful workloads that require consistent uptime.