In which of the scenarios listed here will the unemployment rate fall below the natural rate of unemployment? There could be more than one answer

A. Inflation is steady at 3% for two years but then decreases to 1% for a year.

B. Inflation is steady at 5% for several years.

C. Inflation is steady for 2% for three years, and the Fed unexpectedly increases the money supply, causing inflation to increase to 3% the following year.

D. Inflation is steady at 1% for three years but then increases to 4% for one year.