If the AC Curve in the Above Graph Represents the Minimum

If the AC curve in the above graph represents the minimum of the average total cost curve,then examples of X-inefficiency would best be represented by point:

A) A at output level Q₁ and point D at output level Q₁.
B) A at output level Q₁ and point B at output level Q₂.
C) E at output level Q₂ and point F at output level Q₃.
D) D at output level Q₁ and point C at output level Q₃.