Reject Work Item
The Reject Work Item action allows you to reject the current work item
This is ONLY available from Follow Up actions. DO NOT attempt to use this in the middle of a normal workflow process!!
To "Reject" a work item that work item must have an option button set as the "Default Reject" option. That is how the system knows which button is the one to use in this case.
This action makes no sense in any other context than Follow Up actions. In the normal flow of things you are already moving the workflow forward. Only when it stops is this action useful so Follow Up Actions are the main use for it.