Answer:
The correct answer is letter "A": not restricting trade.
Step-by-step explanation:
Hypothetically speaking a country that is not involved in any trading activity will not have to deal with restrictions. Besides, that country could focus on the specialization of domestic production. However, it is more than likely such a country will need the help of others in the attempt to satisfying the diverse needs of its inhabitants. Countries that prohibit exports and imports nowadays are Cuba, North Korea, Iran, and Syria just to mention a few.