Which of the following subcategories cannot be added to the workflow?

The correct answer identifies "Member" as a subcategory that cannot be added to the workflow. In workflow management, certain subcategories are typically designated for specific functions or processes within a workflow. The subcategories like "Request," "Approval," and "Notification" are integral components of workflows, as they directly relate to the processes involved in task management, decision making, and communication.

"Member," on the other hand, generally refers to individuals or entities that participate in the workflow rather than a functional aspect of the workflow itself. In most workflow systems, members are added to participate in various tasks or actions but do not become a subcategory within the workflow's operational structure like the other options do. Hence, it is not a functional subcategory that can be directly manipulated or modified within the workflow itself.