The Predefined Options Format is one of the many response types used to record the status of a task.
Its primary function is to verify whether a task has been completed or not. If it has, it is checked and recorded by clicking on the button as indicated here:
Format settings can also be modified so that the task is recorded as "Not Specified/Not Checked" (NS/NC).
This allows the user to postpone recording the task and complete it later, with the ability to modify the response and indicate whether it has been executed or not.