Between 2011 and 2012,if an Economy's Exports Rise by $8

Multiple Choice

Between 2011 and 2012,if an economy's exports rise by $8 billion and its imports fall by $8 billion,by how much will GDP change between the two years,all else equal?

A) Net exports will increase GDP by $8 billion.
B) The increase in exports is offset by the decrease in imports, so there is no change in net exports and no effect on GDP.
C) Net exports will increase GDP by $16 billion.
D) Net exports will decrease GDP by $8 billion.