9. A good is produced by a firm in 2009, added to the firm's inventory in 2010, and sold to a household in 2010. As a result, on net,

a. 2009 GDP increased and 2010 GDP decreased.
b. 2009 GDP decreased and 2010 GDP increased.
c. 2009 GDP did not change and 2010 GDP increased.
d. 2009 GDP increased and 2010 GDP did not change.