The covid-19 pandemic forced many firms to temporarily lay-off most of their in-person workers. Since this shock was completely unanticipated, it created an interesting natural experiment for macroeconomists to test their theories. As a result, governments used fiscal stimulus programs to pay newly unemployed workers and central banks massively increased the quantity of money by buying long-term bonds in open market operations. (a) In this context, what do you think is the overall effect on aggregate demand (AD)? O A. no change O B. decrease O C. increase O D. uncertain (b) What is the overall effect on the short run aggregate supply (SAS)? O A. increase O B. no change O C. uncertain O D. decrease (c) What is the overall effect on the long run aggregate supply (LAS)? O A. decrease O B. uncertain O C. no change O D. increase