If Nominal National Income Increased by 10 Percent Over a Certain

If nominal national income increased by 10 percent over a certain period of time while real national income increased by 20 percent, then

A) the price level has declined by about 10 percent.
B) the price level has increased by approximately 10 percent.
C) inflation has occurred during this time period.
D) everybody in the economy became worse off.
E) the labour force increased by 10 percent.