Which statement is true? 

a) Although our economy was not performing well, college graduates from the class of 2012 received more job offers than any other graduating class in history.

b) The economic downturn that began in December 2007 is the longest since the 1930s.

c) Until the time of the Great Depression, the United States was primarily an agricultural nation.

d) There were no recessions during the presidency of George W. Bush (January 2001–January 2009).