All of the Following,except One,would Help to Explain Differences in Purchasing

Multiple Choice

All of the following,except one,would help to explain differences in purchasing power between countries.Which is the exception?

A) Many services are not traded internationally.
B) Financial assets are seldom traded internationally.
C) The existence of transportation and insurance costs.
D) The expression of particular preferences by consumers.
E) The existence of tariffs and other trade restrictions.