Which characteristic of the AWS Cloud enables users to eliminate underutilized CPU capacity?

Elasticity is the correct answer because it refers to the ability of a system to automatically scale resources up or down based on demand. This means users can provision exactly the right amount of compute capacity needed at any given time, eliminating waste from underutilized CPU. Agility refers to the speed and ease with which resources can be provisioned, but doesn't directly address underutilization. Reliability ensures a system can recover from failures and continue operating, while durability ensures data is preserved over long periods, neither of which directly relate to CPU capacity utilization.