You want to delete a group that is currently used throughout Jira.

The statement that is true is that the group is definitely not used to restrict who can invite teammates to Jira. This is because inviting teammates to Jira is a site administration function that is controlled by the site admin role, not by any group. The other statements are false, as the group could be used for those purposes, depending on how the group is configured in the global permissions, the permission schemes, the issue security schemes, or the workflow conditions.