Concept:Management principle that determines how many direct reports a manager can effectively supervise.
Explanation:The principle described is the span of control.
It refers to the total number of subordinates who report directly to a manager.
A manager can only supervise a limited number of employees effectively.
This number is called the span of control or span of management.
Unity of command means each subordinate receives orders from only one superior.
Scalar chain refers to the line of authority from top to bottom.
Unity of direction means all activities with the same objective should have one plan and one head.
Thus, the question’s definition exactly matches span of control.
Answer:D. span of control