Answer:
A. downward-sloping at first but then upward-sloping
Step-by-step explanation:
The long-run average cost curve is typical "downward-sloping at first but then upward-sloping." This can be shown as the long-run average cost curve is graphically represented in a U shape.
The reason is that the long-run average cost of production initially falls as a result of increase returns to scale as output is increased, however, at some stage beyond this certain this, the long-run average cost of production rises because of decreasing returns of scale.