'Costs' is the correct answer because this metric is specifically used to track the financial aspect of resource utilization, helping organizations understand their spending on cloud services. Chargebacks and showbacks are methods of allocating these costs back to the departments or customers responsible for incurring them. Other metrics, like 'Capacity' and 'Connectivity', involve the technical aspects of resource usage and network performance respectively, and do not directly address financial tracking, making them incorrect choices for this question.