The long run aggregate supply curve is vertical.
Explanation:
In the long run, the supply curve is vertical. The reason for this is that the supply curve in the long run will only change when there is a change in the factors of the production which are needed to produce that particular good.
The aggregate demand curve can cause a little change in the total output in the economy but that change would only be temporary and would not be permanent. In the long run, it would be vertical only.