Data on trade barriers and the growth of per capita GDP indicate that Question 9 options:

A. there is no link between the degree of a country's trade openness and its economic growth.

B. more open economies have grown more rapidly than those that have imposed substantial barriers restricting trade.

C. economies that have imposed high trade barriers have, on average, grown more rapidly than economies that are more open to international trade.

D. countries with higher trade barriers have been able to achieve higher levels of per capita GDP than those that are more open to international trade.

E. both c and d are correct.