Please answer the following questions from Part A-D. Thank you!

Consider an economy, starting from the below full employment equilibrium denoted as point A. Please label variables clearly. a. Draw an aggregate demand and aggregate supply (AD-AS) diagram to show that the economy is initially below full employment equilibrium (denoted as a point A) during the COVID19 in March 2020. b. From question (a), If the US central bank (Fed) conducts open market purchase or buys bonds, how does this situation affect the AD-AS diagram? What will happen to the equilibrium price level and real GDP in the short run? Explain your answer. (Please write the new equilibrium point denoted as the point B) c. From question (a), assume that neither the Fed nor the government imposes any policies to simulate the economy. According to the concept of self-correction, in the long run, what will happen in the economy? How is the economy being improved? Explain it in words and graphically, using AD- AS diagram? d. From question (a), how does government use fiscal policy to maintain full employment, using AE model and AD-AS diagram? What is the new equilibrium of real GDP if the government increases spending by $8.8 trillion when the MPC is 0.8? (the government consumption multiplier was around 0.8 in 2020)