Final answer:
In Azure, adding resource groups does not incur direct additional costs; it simply provides organizational benefits, with no impact on cost unless the grouped resources themselves incur costs.
Step-by-step explanation:
Adding resource groups in an Azure subscription does not directly generate additional costs. Resource groups are a way of organizing your Azure resources and managing access to them, which can provide several organizational benefits. They do not affect the cost unless the resources within the group incur costs. Therefore, the correct answer to this question is d) No impact on cost.