Answer to Question 1
Volcker took office in October 1979 in the midst of high inflation and unemployment. Clearly, the long-run aggregate supply curve had shifted to the left. High and unpredictable inflation was undermining incentives to work and to invest. At first, Volcker's appointment only added to the uncertainty: maybe inflation would now come down, maybe not. The decision to lower the federal funds rate in mid-1980 merely stimulated aggregate demand and did nothing to encourage output to recover, so inflation and unemployment remained high. It took more than another year for convincing anti-inflationary policy to allow economic distortions to abate and potential output to rise.
Answer to Question 2
C