The Point of Tangency Between the Short- Run Average Total

The point of tangency between the short- run average total cost (SRATC) curve and the long- run average cost (LRAC) curve occurs

A) at a point where average total cost is falling but the marginal cost is rising.
B) at the point of minimum SRATC.
C) at a point where both the average total cost and the marginal cost is rising.
D) only when the LRAC curve is at its minimum.
E) at an output level for which the quantity of the fixed factor is optimal.