12. A short-run aggregate supply curve shows the A. real output (Real GDP) producers are willing and able to sell at different price levels, ceteris paribus. B. real output (Real GDP) people are willing and able to buy at different price levels, ceteris paribus. C. real output (Real GDP) people are willing and able to buy and to sell at different price levels, ceteris paribus. D. amount of a particular good producers are willing and able to buy at a particular price, ceteris paribus