Suppose that nominal GDP in an economy in year 1 is $500 million and in year 2 is $600 million. If the price level of the goods and services produced has increased from an index number of 120 to an index number of 130 then (select one of the following)

a) while nominal GDP increased between year 1 and year 2, real GDP must have decreased.

b) while nominal GDP has decreased between year 1 and year 2, real GDP must have increased.

c) while prices of the goods and services have increased by 10% between year 1 and year 2, real GDP has decreased by only 5%.

d) while there has been inflation over this period, real GDP has still increased.