What technology helps in automatically adjusting resources based on user demand?

Cloud orchestration is the correct answer because it refers to the process of automating the management, coordination, and arrangement of cloud services and resources. This technology enables the automated deployment, management, and scaling of cloud resources based on real-time user demand. It helps ensure that resources are provisioned seamlessly, scaled up or down, and managed in an efficient manner to adapt to varying workloads.

In scenarios where demand fluctuates, cloud orchestration tools can monitor the system's performance and utilization levels, allowing them to respond proactively by allocating or deallocating resources as needed. This not only optimizes resource usage but also reduces costs and enhances service delivery in cloud environments.

Virtualization plays a role in resource efficiency by enabling multiple virtual instances to run on a single physical machine, but it doesn’t inherently manage or automatically adjust resources based on demand. Automation involves script-based processes to perform tasks but doesn't encompass the higher-level management of coordinating different services and resources that occurs in orchestration. NPV (Net Present Value) calculation, while useful in financial analysis, does not relate to the technical mechanisms of resource management in cloud computing.