Metered utilization is the correct answer because it refers to the characteristic of cloud computing where customers only pay for the resources they use, rather than a flat fee. This means that costs directly reflect actual usage. In comparison, high availability refers to the uptime and reliability of services, rapid elasticity to the ability to scale resources quickly in response to demand, and shared resources to the pooling of resources to serve multiple consumers, but none of these directly correlate cost with usage like metered utilization does.