Which of these is a benefit of using a Community Cloud?

The benefit of using a Community Cloud lies in the cost-sharing among organizations that have shared interests or requirements. In a Community Cloud, multiple organizations collaborate to create and maintain a cloud infrastructure that supports their collective needs. By pooling resources, these organizations can significantly reduce their individual costs associated with cloud services such as infrastructure, management, and maintenance.

This collaboration often leads to not only economic advantages but also fosters a shared responsibility model, which can enhance the infrastructure's overall viability and support. Furthermore, as organizations in a Community Cloud typically share similar compliance requirements or regulatory obligations, they can tailor the cloud environment better to meet specific needs, ensuring efficiency and effectiveness.

Although there might be enhancements in performance or security in a Community Cloud scenario due to shared resource optimization or specific community-driven security policies, these are not guaranteed and would depend significantly on the implementation and architecture. Similarly, the claim of unlimited resources does not hold, as a Community Cloud's capacity would be limited by the resources shared among the participating organizations. Thus, the most definitive and direct benefit related to Community Clouds is the aspect of cost-sharing.