A developer needs a serverless compute option to run backend code in response to database updates. Which service should they use?

Azure Functions is the correct choice because it is a serverless compute service that allows you to run small pieces of code (functions) in response to events, such as database updates, HTTP requests, or timer schedules, without managing infrastructure. Azure Kubernetes Service (AKS) is a container orchestration service, not serverless compute for event-driven code. Azure Virtual Machines provide Infrastructure as a Service (IaaS), requiring you to manage the operating system and software, which is not serverless. Azure App Service is a platform for hosting web applications, REST APIs, and mobile backends, but Azure Functions is specifically designed for event-driven, serverless execution of individual code snippets.