Azure Functions runs in two different modes: Consumption plan and Azure App Service plan. The Consumption plan automatically allocates compute power when your code is running. Your app is scaled out when needed to handle load, and scaled down when code is not running.
Incorrect Answers:
B: When you run in an App Service plan, you must manage the scaling of your function app.
References:
https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-first-azure-function