One challenge faced by the european union is the?
a. inadequate educational and health care systems.
b. continued restrictions on movement between countries.
c. low standard of living compared to communist nations.
d. vast difference in per capita income among states.

The correct answer is D. One challenge faced by the European Union is the vast difference in per capita income among states. This can be seen with Germany and Greece and the tension between the two countries, as German's have a high standard of life while the Greeks are in serious debt and often need to be bailed out. The educational and health systems in the European Union are quite adequate and are usually free and there is free movement between countries, as well as a high standard of living compared to communist nations.

4.a depression is the answer