Answer:
option D is correct which is by summing C + I + G + Xn.
Step-by-step explanation:
A nation's gross domestic product is the dollar value of the total output produced within the borders of the nation and it can be found by summing by C + I + G + Xn.
Option A is incorrect as it is not summing the correct terms.
Option B is incorrect because NDP is always less than GDP
Option C is incorrect because the output is to be produced by citizens within the borders of the country.
So only option D is correct which is by summing C + I + G + Xn.