If Adding Net Exports to C + I + G

Multiple Choice

If adding net exports to C + I + G causes the expenditure line to shift up in a parallel way, it implies that

A) imports and exports are not sensitive to changes in income.
B) both exports and imports are sensitive to changes in income.
C) exports are sensitive to changes in income.
D) imports are sensitive to changes in income.
E) imports and exports have an uncertain effect on income.