Which deployment model allows for autoscaling to accommodate changes in load for an Azure application?

The deployment model that allows for autoscaling to accommodate changes in load is the Azure virtual machine scale set. This model is designed specifically to manage and scale multiple virtual machines automatically. It can dynamically adjust the number of VM instances in response to the demand for an application, ensuring that resources are allocated efficiently based on current loads.

Azure virtual machine scale sets enable automatic scaling based on predefined rules or schedules, allowing applications to handle varying workloads effectively without manual intervention. This capability is essential for applications that experience fluctuating traffic, as it helps maintain performance and cost efficiency.

While other options, such as Azure Functions and Azure App Services, also support scaling capabilities, they do so in different contexts. Azure Functions utilize a serverless model that automatically scales based on event triggers, making it ideal for event-driven architectures but not specifically leveraging a VM scale set approach. Azure App Services provides built-in autoscaling for web applications, but it operates at a higher abstraction level than virtual machine scale sets.

In contrast, the distinction of the virtual machine scale set lies in its granular control over VMs, making it suitable for scenarios that require direct management of virtualized hardware while still allowing for the flexibility of autoscaling.