1. Adobe Workfront Documentation - Create or edit a group status:
"As a group administrator, you can create custom statuses for the groups you manage. The statuses you create are available only for objects associated with that group."
Location: Adobe Experience League > Workfront Documentation > Administrator Guide > Set up Workfront > Create and manage Groups > Create or edit a group status. (This article explicitly details the process described in option B).
2. Adobe Workfront Documentation - System-wide vs. group-specific statuses:
"Statuses can be created for the entire Workfront system or for a specific group. ... When you create a status for a specific group, only users associated with that group can see and apply the status to the objects they work on."
Location: Adobe Experience League > Workfront Documentation > Administrator Guide > Set up Workfront > Project Preferences > Statuses > System-wide vs. group-specific statuses. (This section clarifies the scoping mechanism central to the question).