AZ-900 Practice Question 15: Resource Group Rules

A resource group is a container for resources that share a lifecycle (you deploy, update, and delete them together), and Azure Resource Manager states plainly that when you delete a resource group, all resources in it are deleted too. That is why the guidance is to group resources whose lifecycle really does match.

Option A is wrong because each resource can exist in only one resource group; you may move it to another group, but it is never in two. Cost splitting is done with tags instead. Option C is wrong because resource groups cannot be nested; the scope hierarchy is management group → subscription → resource group → resource, and the resource group is the bottom container. Option D is wrong because resources in a group can live in different regions from the group; the group's location only determines where its metadata is stored, and matching them is a recommendation rather than a rule.

Reference: What is Azure Resource Manager?