Answer: Work should be performed by an individual if "C) the work is simple and does not require diverse input".
Explanation: If the task is very simple, it is uneconomical and illogical to designate more than one person to perform it.
The groups or work teams are used when the task to be performed is complex and the search for a main objective as a whole can only be accomplished by fulfilling the individual objectives of each group member, that is, when there is interdependence between the tasks.