Final answer:
The benefit that ensures that application infrastructure cost and efficiency changes with changing workload is Elasticity.
Step-by-step explanation:
The benefit that ensures that application infrastructure cost and efficiency changes with changing workload is Elasticity. Elasticity refers to the ability of the infrastructure to dynamically scale up or down in response to changes in demand. It allows for the efficient allocation of resources based on the current workload, ensuring that the system can handle fluctuations in traffic effectively.
For example, in cloud computing, elastic scaling allows organizations to automatically add or remove resources as needed, such as increasing the number of servers during peak periods and reducing them during off-peak periods. This flexibility not only optimizes cost but also ensures optimal performance and reliability.