You are building a configuration in Central that will be used for a standardized network...

This is because option C shows how to create a single group in Central with different configuration methods defined for each device type. For example, you can create a group with the name Group1, and within this group, you can enable template-based configuration method for switches and UI-based configuration method for Instant APs and Gateways. Aruba Central identifies both these groups under a single name (Group1). If a device type in the group is marked for template-based configuration method, the group name is prefixed with TG (TG Group1). You can use Group1 as the group ID for workflows such as user management, monitoring, reports, and audit trail2.

https://www.arubanetworks.com/techdocs/central/latest/content/nms/groups/abt-groups.htm  2:https://www.arubanetworks.com/techdocs/central/latest/content/nms/groups/groups.htm