Which AWS best practice ensures the MOST cost-effective architecture for the workload?

Explanations:

Loose coupling is a design principle that promotes minimizing dependencies between services, improving scalability and resilience but not directly impacting cost-effectiveness.

Rightsizing involves adjusting the size of AWS resources (e.g., instances) to match the workload requirements, ensuring optimal performance while minimizing costs. This practice directly contributes to a cost-effective architecture.

Caching improves performance by storing frequently accessed data for quicker retrieval but does not inherently reduce the overall cost of the architecture. It may introduce additional costs if not managed properly.

Redundancy enhances availability and fault tolerance by duplicating resources, which can lead to increased costs without necessarily ensuring cost-effectiveness unless paired with effective cost management strategies.