Which of the Following Is Not a Reason for International

Which of the following is not a reason for international specialization?

A) some countries have educated, trained workers, while other countries have unskilled workers
B) tastes and preferences tend to be different in different countries
C) economies of scale can allow larger, specialized producers to operate at lower average cost
D) mineral resources are often concentrated in particular countries
E) the world price of a good is determined by the world supply and demand for it