The Diagram Below Shows the Domestic Demand and Supply Curves

The diagram below shows the domestic demand and supply curves for denim jeans in Canada.The prevailing world price is PW.Assume that all jeans are identical.
FIGURE 34- 2
-If a country is exporting more goods and services than it is importing,we should consider this to be "beneficial" only in the sense that it

A) represents an accumulation of assets for the domestic economy that can be used in the future to finance consumption.
B) means that an economy is earning more than it is spending.
C) increases the standard of living through a larger national income.
D) is a necessary condition to enable a country to take full advantage of scale economies.
E) allows a country to add to its foreign- exchange reserves above the level needed to cope with fluctuations in private payments.