All of the following are assumed to be constant when the supply curve for a product is drawn, except the:

With railroads, considerable regulatory energy was spent trying to solve the so-called ______________________.

Fill in the blank(s) with the appropriate word(s).

In the above figure, curve A is the ________ curve, curve B is the ________ curve, and curve C is the ________ curve

A) long-run aggregate supply; short-run aggregate supply; aggregate demand B) aggregate demand; short-run aggregate supply; long-run aggregate supply C) short-run aggregate supply; long-run aggregate supply; aggregate demand D) long-run aggregate supply; aggregate demand; short-run aggregate supply