Your company has an Azure Kubernetes Service (AKS) cluster that hosts multiple microservices. You are tasked with deploying a new microservice that processes incoming HTTP requests and publishes messages to an Azure Service Bus topic. The microservice must scale based on the number of messages in the topic, and it must support graceful shutdown to complete in-flight requests. You need to choose the appropriate compute platform. The microservice is stateless and can be containerized. You want to minimize operational overhead and cost. The solution must automatically scale to zero when there are no messages. Which option should you choose?

Option A: Deploy the microservice as an Azure Function with a Service Bus trigger on the Consumption plan. Option B: Deploy the microservice as a container in AKS with a Horizontal Pod Autoscaler based on Service Bus queue length. Option C: Deploy the microservice as an Azure Container App with a Service Bus scale rule. Option D: Deploy the microservice as an Azure App Service WebJob with continuous mode.