Which of the following characteristics of Azure Functions aids in scalability?

The ability to auto-scale based on demand is a fundamental characteristic of Azure Functions that enhances their scalability. Azure Functions operates on a serverless compute model, which means that the infrastructure dynamically adjusts to the workload. When there is an increase in the number of incoming requests or the workload spikes, Azure Functions can automatically provision additional resources to handle the increased demand. This ensures that applications remain responsive and can process large volumes of events and requests without manual intervention.

This auto-scaling capability allows developers to focus on building and deploying applications without worrying about the underlying infrastructure, making it easier to adapt to changing application needs and traffic patterns. As the demand decreases, Azure Functions will scale back down to save costs, optimizing resource usage.

In contrast, fixed infrastructure capacity would limit scalability since it does not adjust to varying loads, while reliance on external resource allocation and dynamic management of application state does not specifically address the automatic scaling aspect that Azure Functions provides.